PAGES -SCIENCE PROJECTS POPULAR

12 PAGES -SCIENCE FAIR PROJECTS

POPULAR

ELECTRONICS Automate Your Slide Projector Build "J" Antenna Build Emitter Dipper New Short -Wave Schedules

SPECIAL D New Uses for Small Recorders

Parlor Games With Tape Report on Heathkit Tape Deck How To Tape Interviews

i

SCIENCE FAIR:

Build `Logic Demon" Binary Counter Tesla's

11117:701 rd 3i63 IS ölidOd Z9bi

NOSNHOr

11601dZObZHOr0bZ079 99E o 3

www.americanradiohistory.com


isands Who Gained

Hugh NRI TRAINING KITS

-EXCITING, FAST

is of NRI gradu- , Industrial Elec- vision and Radio hter futures and Training men to

:ctronics has been y. NRI pioneered home instruction, tg equipment fur - time- proved way train. With NRI ;tter position with ve on to greater latter how much

have, plans

If you served since Janu- ary 31, 1955, or are in

service, check GI line in

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Make $3 to $5 An Hour in Spare Time You don't have to wait until you get an NRI diploma to start earning. As many others have done, you can be making $3 to $5 an hour in your spare -time as you train, fixing radios and TV sets for friends and neighbors. You learn how to install, maintain and service stereo hi -fi, radios, TV sets (including color), even how to charge for service and how to set up your own spare - time or full -time business. Many students pay for their NRI training out of spare -time earnings long before they graduate.

Skilled Technicians Are in Demand There has never been a time when ambitious men with specialized Electronics knowledge were as much in demand as they are today. From television service shops to launching pads, there's a profitable place for you as a skilled technician to help service, operate, install and supervise Electronically -controlled equipment. The NRI diploma is respected and recognized in business and industry. It can be your key to success in America's "glamor" industry.

Achievement Kit Gets You Started Fast As soon as you enroll with NRI we deliver to your door everything you need to make a fast start in the Electronics training of your choice. This new Achievement Kit is an unparalleled example of the value of NRI home -study training. No other school has anything like it. Find out about the NRI Achieve- ment Kit, about NRI training equipment, about NRI courses, about opportunities for success in Electronics. Send for the NRI catalog. There's no obligation. No salesman will call. NATIONAL RADIO INSTITUTE, Electronics Division, Washington, D. C. 20016.

MAIL POSTAGE -FREE CARD NOW

PICK YOUR FIELD FROM NRI'S SPECIALIZED

INSTRUCTION PLANS

1

1

TELEVISION -RADIO SERVICING Complete training from basic fundamentals of electricity to home entertainment equipment. You learn to fix radios, hi -fi and stereo sets, black -and -white and color TV, etc. A profitable field full or part time.

INDUSTRIAL -MILITARY ELECTRONICS From basic principles to computers. Compre- hensive training teaches fundamentals, then, takes you into such modern -day miracles as servos, telemetry, multiplexing, phase cir -j cuitry, others.

COMPLETE COMMUNICATIONS* Teaches you, with actual practice, operation, service and maintenance of AM, FM and TV broadcasting stations. Also covers marine, aviation, mobile radio, facsimile, microwave, radar.

FCC LICENSE* Prepares you for your First Class FCC Radio- telephone License examinations. You begin with a thorough background in fundamental Electronic principles, advance to required subjects covering equipment and procedures.

MATH FOR ELECTRONICS A brief course for engineers, technicians who need a quick review of essential math used in industry, communications, government. Basic arithmetic review, shortcut formulas, modern digital number system, much, much more.

BASIC ELECTRONICS A concise course in Electronic terminology and components. A wealth of useful information to help you better understand the field. For anyone who wants basic understanding of Radio - TV Electronics.

ELECTRONICS FOR AUTOMATION Not for beginners. Offered for men with some knowledge of Electronics who want better understanding of process control, ultrasonics, telemetering, and remote control, electrome- chanical measurements, other subjects.

AVIATION COMMUNICATIONS* This course prepares you to install, maintain, service aircraft communications equipment. Covers direction finders, ranges, markers, Loran, Shoran, Radar, landing systems. Earn your First Class FCC License with Radar Endorsement.

MARINE COMMUNICATIONS* Covers transmitters, direction finders, depth indicators, radar, sonar, other equipment used oit commercial ships and thousands of pleasure boats. Prepares you for a First Class FCC License with Radar Endorsement.

MOBILE COMMUNICATIONS* Learn to install and maintain mobile equipment and associated base stations. Covers transmitters and receivers used by police and', fire departments, public utilities, construction I

projects, taxis, etc. Prepares you for FCC License.

ELECTRICAL APPLIANCE REPAIR Prepares you quickly to repair all types of appliances, including air conditioning, refrigeration, small gasoline engines. An easy, practical course leading to profitable part -time or full - time business of your own.

ELECTRONICS FOR PRINTERS Designed to teach operation and maintenance of Electronic equipment which controls the latest devices developed for the graphic arts industry. From basic principles to computer circuits. Approved by major manufacturers.

*NOTE: You must pass your FCC License exam (any Communications course) or NRI refunds in full the tuition you have paid.



The Oldest and Largest

School of its Kind

in America

WHERE YOU TRAIN IS AS IMPORTANT

AS YOUR DECISION TO TRAIN

At NRI you are backed by 50 Years of

leadership in home -study training for

Electronics Automation TV Radio

J. E. Smith, Founder -1914.

Fifty years ago, a school teacher named James E. Smith started giving extra instruction to four of his students in the "mysterious" new field of radio. From that small beginning, National Radio Institute has grown to be America's largest home -study school in the many fields of Electronics. Nearly three -quarters of a million students have enrolled over the years. This vast experience is behind NRI's

meaningful, interesting, easy -to- understand methods of training; methods that make Electronics a practical isoubject for almost anyone to learn no matter how much r how little formal education he has. But experience is only the base upon which NRI is

%puilt. Today there is a staff of more than 150 dedicated people working with you as a "class" of one, keeping training material up- to- the -minute, providing consultation services as you train, advising you about new developments in Electronics, even helping you with job placement when you're ready. Ask men whose judgment you respect about NRI training. And send for the catalog we offer. Read about opportunities in Electronics, about new developments, about NRI itself and the variety of training plans open to you at reasonable

-cost. Mail the postage -free card today.

JOIN MEN LIKE THESE - TRAIN FOR SUCCESS WITH NRI

"I went into my own business six months after finishing the NRI Radio - TV Servicing Course. It makes my family of six a good living. We repair any TV or Radio. I would not take anything for my training with NRI. It is the finest."

DON HOUSE, Lubbock, Texas

"Many thanks to NRI for the Elec- tronics training I received. I hold a first class FCC License and am employed as a studio and master control engineer /technician with KXJB -TV."

RONALD L. WOOD, Fargo, N.D.

"I am a Senior Engineering Aide at Litton Systems, in charge of checkout of magnetic recording devices for our computers. Without the help of NRI I would probably still be working in a factory at a lower standard of living."

DAVID F. CONRAD, Reseda, Calif.

"NRI training enabled me to land a very good job as Electronic Technician with the Post Office Dept. I also have a very profitable spare -time business fixing Radios and TV."

NORMAN RALSTON, Cincinnati, Ohio



POPULAR ELECTRONICS WORLD'S LARGEST -SELLING ELECTRONICS MAGAZINE

VOLUME 25 DECEMBER, 1966 SCIENCE FAIR PROJECTS

DON LANCASTER 41

DON LANCASTER 57

ARTHUR S. COOKFAIR 70

NUMBER 6

THE LOGIC DEMON Getting to know NOR, NAND, and some other gates

WANT TO BUILD AN INTEGRATED CIRCUIT BINARY COUNTER? Visual demonstrator of how binary addition works

TESLA'S THERMOMAGNETIC MOTOR Curie temperature effects produce reciprocal motion

FEATURE ARTICLES ALBERT S. VON TROTT, W3UIX /6 46

ROBERT N. TELLEFSEN, W7SMC /0 47

J. W. NELLIGAN 50 HERB HOWORKA, JR. 52

A. A. MANGIERI 54 GARY W. TOWNER 55

AL JOHNS 62 LEWIS A. HARLOW 63

LEWIS A. HARLOW 65 66

68 72

ROBERT P. BAHN 73 LOU GARNER 74

HERB S. BRIER, W9EGO 77

MATT P. SPINELLO, KHC2060 79

ROBERT LEGGE 60 HANK BENNETT, W2PNA 81

BILL LEGGE 82 84

110

THE "SCROUNGE " -AN INSTANT "J" ANTENNA BUILD THE EMITTER DIPPER Solid -state battery -operated wide -range test instrument for all experimenters

ST. PETERSBURG TAPERS GO BACK TO SCHOOL SMALL TAPE RECORDERS You con do more than whistle into those inexpensive jobs

SOLDERLESS BREADBOARD

"RELAXATROL" TO AUTOMATE YOUR SLIDE PROJECTOR ALL ON QUARTER -INCH MYLAR HOW TO CONDUCT AN INTERVIEW WITH A TAPE RECORDER Stenos now push buttons instead of pencils PARLOR GAME A TAPE RECORDER KIT -DELUXE New recorder con be built in less than 18 hours

ZERO -BEATING THE NEWS

JUST WHEN I FORGOT MY (SOLDERING) GUN: SEQUEL 3 BRIDGE CIRCUIT QUIZ SOLID STATE

AMATEUR RADIO Getting the most from your dipole or beam antenna

ON THE CITIZENS BAND CB HELP plan tested

ENGLISH -LANGUAGE BROADCASTS TO NORTH AMERICA SHORT -WAVE LISTENING Broadcasting station news around the world

FOREIGN- LANGUAGE BROADCASTS TO NORTH AMERICA ELAPSED TIME INDICATOR KEEPS TRACK OF STYLUS WEAR DX STATES AWARDS PRESENTED

DEPARTMENTS

Checking out the Curie temperature effect

6 14 15 22 26 28 30 88

112

LETTERS FROM OUR READERS

TIPS & TECHNIQUES

READER SERVICE PAGE

NEW PRODUCTS

ELECTRONICS LIBRARY NEW LITERATURE

OPERATION ASSIST

OUT OF TUNE

INDEX TO VOLUME 25 (JULY -DEC., 1966)

Presenting a potpourri on tape recording

POPULAR ELECTRONICS is indexed in the Readers' Guide to Periodical Literature

This month's cover photo be Conrad Studios. Inc.

Copyright c 1966 by ZIFF -DAVIS PUBLISHING COMPANY. All rights reserved. POPULAR ELECTRONICS, Dec,otb,r 1 9Gú I ohms, , .Auu/b,; r;, f'rsttished monthly at 3517 North .11iehigart d errirr. Chicago, Illßnia (ìr/tio 1. lhoc yell, swiss,, .o, ion rat, far U.S., I ,o, /',. r.".,.' .'' and Ca oad,t, $:i.11ll; all ctltcr countries, .$0.00. Second Class Ilr,. +(uge Zraisi ttt Chicago, Illinois and nth,, mailing officer. Sobs', ilrt ion .0. I' mtland Place, Boulder, Colorutlo 8n30.2.



DEVRY TECH NOT ONLY TRAINS

YOU ... BUT HELPS YOU GET

STARTED AT NO EXTRA COST IN

THE ß1 i -3t 10 1 % ¡J') OF

HOME LABORATORY EQUIPMENT

- YOURS TO KEEP!

EUanamocsQ VPREPARE AT HOME

Whether you want to prepare for a goodpaying new job or for advancement in Electronics with your present employer, DeVry Tech offers specialized educational programs designed to meet your needs. You set up your own HOME LABORATORY and work over 300 construction and test procedures to develop on- the -job type skills. You build a quality Transistorized Meter, a 5 -inch Oscilloscope and a special Design Console. DeVry also includes modern "programmed" texts, instructive motion pictures, Consultation Service. Effective? Yes!

VRESIDENT SCHOOL If you prefer you may get all of your training in DeVry's

U.S. or Canadian resident schools under the close guidance of friendly, experienced instructors. You work with a wide variety of commercial equipment similar to that actually used in industry as you prepare in our laboratories for a technician's job in Communications, Microwaves, Radio -Television, Automation, Radar, Computers, or other branch of Electronics. DeVry even provides part-time job placement service to those who wish to earn extra money while attending day or evening classes.

VPLACEMENT SERVICE Meet W. E. Bartz, who has helped thousands of DeVry

men toward exciting, profitable careers in Electronics. When YOU complete your program, he will help you too. As Placement Manager in touch with business and industry across the nation. Bartz knows the employer demand for DeVry- trained men. He has cooperated in placing our graduates with thousands of firms!

Men 18 -45, start preparing NOW for this vast opportunity field. Soon you should be ready for DeVry's valuable employment help!

I MA COUP 0A/ TODA y! No Advanced Education or Previous Technical Experience Needed to Get Started Your ambition and desire to suc-

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DEVRY TECHNICAL INSTIT 4141 Belmont Avenue + Chicago, Illinois 60641

Accredited Member of Nat,onrl Home Study Council

December, 1966

DeVRY TECHNICAL INSTITUTE 4141 Belmont Avenue, Chicago, III., 60641 Dept. PE -12 -W Please give me your two free booklets, "Pocket Guide to Real Earnings," and "Electronics in Space Travel "; also include details on how to prepare for a career in Electronics. I am interested in the following opportunity fields (check one or more):

Space & Missile Electronics Communications Television and Radio Computers Microwaves Broadcasting

El Industrial Electronics Automation Electronics Electronic Control

Name Age

Address Apt Zip

City State Code Check here if you are under 16 years of age.

HOME STUDY AND RESIDENT SCHOOL TRAINING 2103 AVAILABLE IN CANADA

3



put a price on your equipment!

Then add this one, and stop heat from robbing you of component life. The Hi Fi Boxer fan can return its cost 10 times or more by increasing the life of the average color TV or Hi Fi set. Save money with fewer service calls, fewer replacements and better performance. This unit, made by the company that produces airmovers for computers, broadcasting equipment, and the Minuteman missile is now available in the new long -life Grand Prix model at no extra cost. Avoid plastic substitutes, get the real Grand Prix from your nearest Hi Fi dealer or write:

IMC Magnetics Corp New Hampshire Division, Route 16B, Rochester, New Hampshire 03867

POPULAR ELECTRONICS PHILLIP T. HEFFERNAN

Publisher

OLIVER P. FERRELL Editor

ROBERT CORNELL, WA2HDQ llnnagin0 Editor

JOHN D. DRUMMOND Trrhn,cal Editor

WILLIAM GALBREATH Irt Director

MARGARET MAGNA 4,,acinte Editor

ALEXANDER W. BURAWA Assistant Editor

ANDRE DUZANT I.rhnrrt Illustrator

NINA KALAWSKY Editor lot Assistant

PATTI MORGAN Editorial Assistant

H. BENNETT, W2PNA H. S. BRIER, W9EGQ

L. E. GARNER, JR. M. P. SPINELLO, KHC2O6O

Contributing Editors

LAWRENCE SPORN A,/rerHSing Sales Alpneger

ARDYS C. MORAN Adre,tl.sing Service Manager

ZIFF -DAVIS PUBLISHING COMPANY Editorial and Executive Offices

One Park Avenue, New York, New York 10016 212 679 -7200

Eastern Advertising Manager, RICHARD J. HALPERN

Midwestern Office 307 North Michigan Avenue, Chicago, Illinois 60601

312 726 -0892 Midwestern Advertising Manager, JAMES WEAKLEY

Western Office 9025 Wilshire Boulevard, Beverly Hills, California 90211

213 CRestview 4 -0265; BRadshaw 2 -1161 Western Advertising Manager, BUD DEAN

Japan: James Yogi c/o Fukushima

19 -14 Minami 3 -chome Koen¡i, Suginami -ku

Tokyo, Japan

Circulation Office Portland Place

Boulder, Colorado 80302

William B. Ziff, Chairman of the Board (1946 -1953) William Ziff, President

W. Bradford Briggs, Executive Vice President Hershel B. Sarbin, Vice President and General Manager

Philip Sine, Financial Vice President Walter 5. Mills, Jr., Vice President, Circulation Stanley R. Greenfield, Vice President, Marketing

Phillip T. Heffernan, Vice President, Electronics Division Frank Pomerantz, Vice President, Creative Services

Arthur W. Butzow, Vice President, Production Edward D. Muhlfeld, Vice President, Aviation Division

Ziff -Davis also publishes Skiing, Flying, Business & Commercial Aviation, Boating. Car and Driver. Cycle, Popular Photography. HIFI /Stereo Review. Electronics World. Modern Bride, Skiing Trade News. and Skiing Area News. An subscription correspondence should be addressed to POPULAR ELECTRONICS. Circulation Department. Portland Place, Boulder. Colorado 80302. Please allow at least six weeks for change of address. Include your old address. as well as new -enclosing if possible an address Mite] from a recent issue. EDITORI AI. CONTRIBUTIONS must be accompanied by return postage and toil I be handled

i Illty for return reasonable

afety ohowever. art rk. pphoto- assumes no gra pits or manuscripts.

or safety ar we

o\nuuia o Member Audit Bureau

of Circulations

CIRCLE NO. 19 ON READER SERVICE PAGE 4 POPULAR ELECTRONICS



On -Off Volume Squelch

r...._.1111

Channel

Simp The new 725 is two knobs simple. Push the left one, it's on; turn the right one to any of 8 channels. Now you're ready to broadcast on the first 5 watt mobile transceiver designed to be operated by any member of the family. Forget about noise. A built -in jack lets you use it with your headset to eliminate loud outside noises.

The 725 is packed with performance, too. Inside, this compact (81/2" x 6" x 2 ")

is loaded with solid state circuitry and 14 silicone transistors. Outside, it's designed with the high -style of standard dashboard equipment. At $119.95, it looks like the 725 belongs under the dashboard of your Ferrari, T -Bird .. .

or your Chevrolet!

I e To learn more about the new 725 -

and the entire Amphenol solid state line -just drop into your nearest Amphenol two -way radio headquarters.

Or write Amphenol, Box 134, Broad- view, Illinois 60153.

AMPHENOL CIRCLE NO. 2 ON READER SERVICE PAGE

December, 1966 5



...the most wanted feature on record player units today is now available in models from $54.50 ...a revolutionary development! The Garrard cueug controls eliminate the danger of accidental damage to records or stylus through manual handling; work three ways: 1. To lower the tone arm gently to the record without manual handling. 2. To pause (and then continue when ready) during single or automatic play. 3. To locate any record groove accurately and safely. Built -in cueing controls are featured on three of Garrard's new automatic turntables:

LETTERS FROM OUR READERS Address correspondence for this department to:

Letters Editor, POPULAR ELECTRONICS One Park Avenue, New York, N. Y. 10016

AUTO BATTERY- OPERATED TAPE RECORDER

A friend of mine says I can run my 6 -volt tape recorder motor on a 6 -volt automobile battery, and that the motor would just use the current it needs. But one of my teachers says that it would burn out the motor. Who is correct?

DALE R. TROTMAN Mayo, Fla.

We don't like to disagree with one of your teachers, Dale, but we can't see how you could possibly damage a 6 -volt d.c. motor on a 6 -volt battery regardless of the physical size of the battery. Your teacher might be taking into

50 MK II -$54.50

with manual using and pause

control lever built into the tone arm system.

60 Mk II

-$74.50 With manual

cue ng and pause cortrol lever built

into the tone arm system.

LAB 80 Mk 11

-$99 50 with exclusive

ydrauk_ ally operated cueing tab control

conveniently built into the tone arm rest.

These are three of five Garard Automatic Turntables just introduced. For complimentary copy of colorful new Comparator Guide describing all models, write Garrard, (Dept, GX -356, Westbury, N.Y. 11590.

CIRCLE NO. 47 ON READER SERVICE PAGE

6

account the voltage rise from the generator when tite engine is t°tettnittg. Aside from possible tape speed variations, the tape recorder motor -if it is actually a 6 -volt unit -should be able to handle a nominal increase in voltage. However, you can run into a problem with the transistors and other electronic components if rr higher voltage source is used.

DROOPED DECIBEL GRAPH

In your article "What Are These Things Called Decibels ?" (October, 1966), is the graph on page 76 in error? It looks as though the reference lines are displaced downward from where they should be.

O. R. HEINZ, K7KHA Reno, Nevada

There seems to be a discrepancy in the "AC VOLTS TO DB GRAPH," or did I mis- interpret the article?

ARTHUR S. Dt'BUAR Toms River, N.J.

See "Out of Tune" on page 89.

"SCROUNGING" FOR AN ANTENNA

I am a registered Short -Wave Monitor (WPE6GOC), and I am now studying for my

POPULAR ELECTRONICS



Why does one of these men earn so much more than the other? More brains? More ambition?

No, just more education

in electronics. You know that two men who are the same age can work side -by -side on the same project, yet one will earn much more than the other. Why? In most cases, simply because one man has a better knowledge of electronics than the other. In electronics, as in any technical field, you must learn more to earn more. And, because electronics keeps changing, you can never stop learning if you want to be successful. But your job and family obligations may make it almost impossible for you to go back to school and get the additional education you need. That's why CREI Home Study Programs are developed. These programs make it possible for you to study advanced electronics at home, at your own pace, on your own schedule. You study with the assurance that what you learn can be applied on the job to make you worth more money to your employer. CREI Programs cover all important areas of electronics including communications, servo -mechanisms, even spacecraft tracking and control. You're sure to find a program that fits your career objectives. You're eligible for a CREI Program if you have a high school education and work in electronics. FREE book gives all the fart- Mail coupon or write: CREI, Dept. 1212 -D, 3224 Sixteenth Street, N.W., Washing- ton, D.C. 20010.

Send for Free Book ACç,e , th,. N.lt,nn::l Hnm. Stuff, Council

CREI FounJed 1921

December, 1966

NOW! 2 NEW PROGRAMS! Industrial Electronics for Automation

Computer Systems Technology

r The Capitol Radio Engineering Institute Dept. 1212 -D, 3224 Sixteenth Street, N.W, Washingtol, D.C. 20010

Please send me FREE book describing CREI Programs. I am employed in electronics and have a high school education.

NAME AGE

ADDRESS

CITY STATE ZIP CODE

EMPLOYED BY

TYPE OF PRESENT WORN

CI BILL

I am interested in 17 Electronic Engineering Technology Space Electronics -: Nuclear Engineering Technology

NEW! Industrial Electronics for Automation NEW! Computer Systems Technology

L Approved for Veterans Administration Training

7



E

GIFTED COMMUNICATIONS by &-.-Wl eAtcsi_ for every purpose. , ,every purse

The Incomparable 23 Channel Range Gain II $23500 No other CB set, at any price, can match the Double Side -Band, Reduced Carrier performance that Range Gain II gives on all 23 channels. You get up to 4 times more coverage and 30 watts P. E. P. modulation capacity in base or mobile applications. Try it once ... and you'll like it forever!

The 12 Channel

$110 00 Solid State Charger... Our Metrotek Charger offers more channels at less cost. This smooth running DC powered mobile set has

13 silicon transistors and 5 diodes for peak performance on all 12 crystal controlled channels. And the low price includes mike, mobile mounting bracket, adjustable squelch and built -in A. N. L. plus remote speaker, P. A. capability and crystals for channel 11.

The Popular, $110.00 Versatile Pacer II

The economical, CB transceiver that is at home in base or mobile installations. 11 crystal controlled channels on transmit and receive plus 23 channel tunable receiver. Works equally well on AC or transistorized DC power supply. The Pacer's illuminated "S" meter, spotter switch and adjustable squelch are extras that enable the Pacer II to give you so much for so little money.

The Ultra Special Regency Ranger $115'00 This is the compact transistorized set with a long list of exclusives. The up front speaker, Collins mechanical filter, a dial system with channel numbers and big TO -3 power transistor are just a part of the construction features that make the Ranger the best of all CB mo- biles. Join the rangers ... you'll get your man on any of its 11 powerful channels!

The Transistorized, Needle Busting Bronco $89.95

Here is the transceiver that has broken the CB price barrier. It gives crystal controlled performance on 8

channels. 13 silicon transistors and

5 diodes deliver maximum efficiency for your 2 -way radio dollar. The streamlined circuitry includes built -in A. N. L. and adjustable squelch control. The Bronco comes complete and ready to operate with mike, mounting bracket and channel 11 crystals plus remote speaker capability.

Every Regency and Metrotek transceiver gives you a

1 year warranty

ELECTRONICS, INC. 7900 PENDLETON PIKE INDIANAPOLIS, INDIANA

CIRCLE NO. 33 ON READER SERVICE PAGE POPULAR ELECTRONICS



e----9'$c*. monitora io

for listening to Police Calls Fire Calls

Aircraft Radio

Model DR -200 with Matching Speaker Tunable for both high (152 -174 MHz) and low (30 -50 MHz) bands. Provisions for 1 crystal con-

trolled frequency in both high and low bands.

Models MR -10B (152 -174 MHz) and MR -33B (30 -50 MHz) FM Receivers

Tunable with illuminated slide rule dial, 5" speaker and power transformer. Provision for external speaker or head phones.

e tr e

Model AR -136 Flight Monitoradio Tunable from 108 -136 MHz for listening to con-

versations between airplanes and control towers. Crystal controlled model also available.

Model 2MH -2 (152 -174 MHz) and TM L-2 (30 -50 MHz) Transistorized Monitoradio

The ultimate in emergency receivers. Up to 6

crystal controlled frequencies in high or low band. 3 -way power supply keeps the receiver on

call at all times ... in home or car and all points in between.

All Regency Monitoradios are built to professional standards to deliver strong readable signals. Each gives you a 1 year warranty. Get your favorite today for hours of listening pleasure.

Choice of 11 Regency Models Priced from $69.95

December, 1966

LETTERS (Continued from page 6)

Novice license. I plan to get the Heathkit "Two -er" and operate phone on 2 meters, but I live on the first floor of a two -story apart- ment and have an antenna space problem.

DAVID KELLY Los Angeles, Calif.

Fortunately, David, 2 -meter antennas are quite small, and there are a number of good antennas available commercially; but you might be interested in what you can do with a piece of flat .300-ohm transmission line the kind used for TV work. Try rigging up "The Scrounge An Instant J Antenna," described on page 46 in this issue. For 2 meters. the total length of the antenna is only 54.9 inches. The half -wave section is 38.2 inches and the quarter-wave section is 16.7 inches.

POPULAR ELECTRONICS INDEX

I have a complete set of P.E. issues from Vol. 1, No. 1 (October, 1954) to the present. I am constantly called upon in my work to come up with different electronic devices to solve all kinds of problems, and I have found many solutions and shortcuts in your fine publication. Would it be possible for you to perforate the Table of Contents page in each issue so that I can tear them out and fit them into a suitable file?

AL DIAMOND New York, N.Y.

Al, your suggestion is appreciated. How- ever, since most readers don't like to cut up their issues, we would rather spend the money

fill IIIIIIIO 111111111 110 hrll m,. .íR--, ,rr lino u n' h It ern

117oUibwwli r ' Mr lb ID.

I` MIMI IIIIIII6tlIlr lálturi'uI ulr,umutI lldnr 1i1 rr i t ammni tlluIII

M IiIITITi

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for editorial material than for perforations. Are you using our Volume Index which is published in the June and December issues? For the latest semiannual index, see page 112.

BARIUM TITANATE NOT OUT OF DATE

We do not believe that barium titanate is out of date as indicated by the letter in your July, 1966, issue from C.P. Germano of the Clevite Corp. Barium titanate (or the modified titanate) is the most commonly used ceramic piezoelectric transducer material in existence. Barium titanate has been replaced in the ceramic phono cartridge application by the newer lead zirconate -titanate material. This replacement was accomplished because the lead zirconate- titanate seemed to work better in the old standard designs. More

9



TRAIN AT HOME FOR

ELECTRONICS s Radio .Television Data Processing Computers '

Telecommunications Telemetry Industrial Electronics

Get yourself 11 into ELECTRONICS,

the greatest field of opportunity today. ,._.


sophisticated designs with barium titanate elements have greatly outperformed the lead zirconate- titanates, but never gained wide popularity. In general, the lead zirconate- titanates exhibit both advantages and dis- advantages when compared with barium titanate.

JAMES W. ANDERSON Linden Laboratories, Inc.

State College, Pa.

TV DX IN GREECE

The article on "Riding the TV DX Trail" (July, 1966) was interesting. During the sum- mer, especially in the afternoons (Greek time), I have received transmissions on Chan- nels 2 and 3 from Germany (920 miles), from

CAN BECOME A PART OF THE4-

ELECTRONICS WORLD TODAY: , SEND FOR

ELECTRONICS SELECTION CAREER,----- KIT __

rYes, I m interested in the Electronics Field. Piee eur FREE ' 'ELECTRONICS CAREER SELECTION KIT. I understand there is no obit- !gallon.

IOccupation Age

'Name

¡Address

_.._.;

kity State Zip

TECHNICAL TRAINING INTERNATIONAL, Inc.;

L10447 South Torrence Avenue Chicago, Illinois 60617

, "<°`, -Opel a 2uant.os a euctotey °á Vent" Vede Pwlieaaio.cal $tiaiis.cee

Grr 72alKC4lj Not"

Spain (1470 miles), and from Italy and Czecho- slovakia (980 miles). I enclose a picture from Spanish television TV- ESPANA which I took last year.

Dim. GAGOSSIS Athens 811, Greece

D.C. FLUORESCENT LIGHT

I thought you might be interested in my adaptation of the "D.C.- Operated Fluorescent Light" (July, 1965). Not having any use for a self- contained portable unit, I separated the power supply from the fluorescent tube holder in order to obtain a slim light source for mounting in a car. The lamp holder is made from two pieces of 12" x 1" aluminum angle, and has a piece of translucent fiberglass over the front. The lamp is mounted on a swivel Kleenex holder and can swing out to face the driver. It works like a charm.

JOHN W. KINDLES" Birmingham, Mich.

FLUX TO END ALL FLUX

In "Solid State," (March, 1966), page 90, second column, third paragraph, I read about "an ordinary alligator clip to which a piece of felt is soldered." Now, I thought I knew all about soldering, but apparently Lou Garner is way ahead of me. Can you tell me what

10 POPULAR ELECTRONICS



Out where the test begins -a man needs

HALLICRAFIERS reliability!

Beyond the last outpost . . . where communica :ion is a necessity, not a

parlor game ... don't settle for less than the quaity of workmanship and un- failing performance that have made Hallicraf:Ers products known throughout the world as "the radioman's radio".

CB -11A 10- transistor citizens band pocket portable. 100 mw. of power ... rangy up to three miles ... battery life indica:o! ... Price: $74.95 /pair.

ha11 crafiers 5th & hostner Aves., Chicago, III. 60624

Export: Internet,icnal Div. Canada: Gould Sales Co.

CIRCLE NO. 17 ON READER SERVICE PAGE December, 1966 11



FOR MOBILE OPERATION The 23 channel DIRECTOR OR The 11 channel ESCORT H

AND FOR BASE STATION The 23 channel GUARDIAN

Performance matched for peak efficiency, the All Solid State Director or Escort II in your car, truck or tractor teams with the Guardian 23

base station command unit to give you the finest two -way radio communications network in the

nation! SEE IT! TRY IT! BUY IT!

ALL SOLID STATE

CB'S

DIRECTOR - 23 Channel CB $269.90 (complete with crystals for 23 channels)

ESCORT II- 11 Channel CB (complete with crystals for 6 channels)

$219.90

GUARDIAN 23 -23 Channel CB $269.90 (complete with crystals for 23 channels)

PEARCE -SIMPSON, INC. PE -1266

P.O. BOX 800 -Biscayne Annex, Miami, Florida 33152 Please send full information and model specifications on the Director, Escort"( and Guardian 23,

Name

Address

City State

PEARCE SIMPSON, INC. MIAMI, FLORIDA

CIRCLE NO. 31 ON READER SERVICE PAGE 12


type of flux your Semiconductor Editor uses when he solders felt?

BILL ROBERTS Reno, Nev.

Felt flux, of course, but we don't know where to get it. Bill, while we generally think of a metallic union when we think of solder, we can also get burned by the stuff, in more ways than one. Don't blame Mr. Garner for this slip of the typewriter; actually, if you look up the word solder in the dictionary, you'll find a definition reading: something that unites or cements. A problem of seman- tics'

HYDRONICS, HUM AND SKEPTICISM

It was with the greatest of skepticism that I constructed the Hydronics receiver described in the article "Is Plasmonics For the Birds ?" (July, 1966). I was greatly surprised when I turned it on, and heard in my head- phones chirps and short warbles. I used the dipole antenna which I held over the side of a rowboat in a lake at a day camp at Armonk,

N.Y., where I am a C.I.T., and act as an assistant to the science counselor. My congratu- lations to Mr. Minto on his interesting dis- covery.

ELLIOTT SHARP White Plains, N.Y.

I built the Hydronics receiver, and it works fine with a microphone; but when I plug in the antenna, there is a loud hum. I have gone to all the TV and radio shops around town and nobody can help me. Can you?

D. A. STAN Griffith, Ind.

I successfully detected several types of un- derwater signals using equipment similar to that described in your article: a 4' dipole antenna with 2" x 3" copper plates, an Olson AM -260 300 -mW, 5- transistor amplifier, and a 4" speaker. Whenever the antenna was in the water (but not when it was out of the water), a 60 -Hz hum could be heard. Also a crackling and popping sound was always present. There was never more than about a half a second interval between successive bursts of crackling. And I was unable to observe any directional effects in the intensity of the noise

(Continued on page 88)

POPULAR ELECTRONICS



5-Band Portable CB Receiver /Direction Finder Here is Nova -Tech's solid state 5 Band Portable. It picks up all CB channels, entire Marine Band, Low Frequency navigation beacons, weather stations, and standard broadcasts. It's also an accurate navigation instrument, used in thousands of planes and boats for position finding and homing.

1. CB Low

2. CB High

3. L. F.

4. S. W.

5 Bands Tunes all 23 channels spread out on 2 bands for easy tuning and positive identification. You can monitor all CB channels wherever you go... including H. E. L. 1'. and R. E. A. C. T.

200-400 KC. Beacon /Weather. Hear accurate, up- to -the- minute weather broadcasts around the clock. FAA stations give all weather data for 200 miles around. Also tunes navigation beacons.

1.4 -4.5 MC. Marine /Shortwave /Police. Listen to all marine communications: ship -to -ship, ship -to- shore, Coast Guard, fishing and pleasure boats. MAYDAY. Radio hams on 75 meter band.

5. A.M. Standard broadcast band. music, news, sports. Sensitive receiver brings in stations ordinary radios just can't get.

Hours Of Fascinating Listening

Technically, this unit is superb. The CB section uses a 2

crystal, double conversion circuit to shift the entire 27 Mc CB hand clown to the 200 Kc region and by means of a tunable IF strip and a narrow band mechanical filter, a stability is produced that rivals laboratory instruments. 1 microvolt sensitivity is produced by 2 BF transistors ahead of the mixer. The adjustable squelch control can be set so that as little as 3 microvolts will unlock the audio. The S meter also serves as a null meter when direction finding on the lower hands.

Nova CB combines a superb CB receiver with an outstanding portable direction finder, of which over 50.000 are now in use, more than all other makes combined. Useful and handsome, this unit will be valued for many years.

Can operate 4 ways: from internal batteries, external dry cell, house current, or sun power from optional solar cells. ($40 extra.)

The new Nova -Tech NOVA CB is a long range 5 -band receiver and radio direction finder with exclusive features.

11

I "NULL" METER Locates direction instantly.

2 SQUELCH CONTROL eliminates noise and static between CB transmissions.

3. ROTATING ANTENNA gives sharp, clean nulls to give accurate bearings. No need to rotate entire set

E. DE LEVEL CONTROL adjusts needle sensitivity. Also prevents overload from strong signals which could prevent sharp, accurate nulls.

'i IRO' LEFT -RIGHT BEARING SCALE gives accuracy of 10" diameter compass rose even though set is only 21/4" thick.

December, 1966

C MORSE CODE. a handy guide to help identity beacon signals.

7 CALIBRATED OPTICAL SIGHTS on rotating antenna flip up for taking visual bearings.

H REMOVABLE BRACKET is adjustable for horizontal or vertical mounting and can be used as carrying handle.

9. TWO EXTERNAL HEADPHONE JACKS, one for standard headphone, one for miniature ear- piece (Included free).

ID. TWIN PLUG IN EXTENOABI E

ANTENNAS for the best mobile reception.

II. LONG RANGE EXTENDABLE REMOVABLE WHIP provides maximum signal input on ground.

12. BUILT IN EXTERNAL CB ANTENNA JACK for roof top or car top antenna. Provides greater range.

13. PUSH BUTTON DIAL LIGHT illuminates entire slide rule calibration scale for easy and accurate tuning at night.

14. BATTERY '.vER PLUG. External batteries can be con. netted. Also comes with house current adapter.

A SPEC1; ACULAR CHRISTMA

5 Band Portable CB Receiver/ Direction Finder $149.95

Over 50,000 Nova -Tech radio direction finders now in use all over the world ... more than all other makes combined.

Complete with 3 telescoping whip antennas, miniature earphone, leather carrying case, batteries, removable and adjustable mounting bracket. Only 8" x 5" x 2 ", smaller than an ordinary cigar box, it weighs just 21/2 lbs. Arid it also ¡thugs into regular house current.

5 Band Nova CB 149" Budget terms available, $40 down $20 month or charge your Diners Card.

A BOAT NAVIGATION

POSITION FINDING

Y 1 Y L Y ̀ r l' iV 1 í Y. 9 i YEViC Y Y. Y` r. 9 S C Ife 1 Y íY Y iY Y` C YY YaY Ya ̀ C 'y

UNCONDITIONAL MONEY BACK GUARANTEE

T If you are not completely pleased with your Nova CB return it within 30 days for full refund. No questions. No explanations. y.

r _;ÚCJ,aA'y. tax tu.C,1111raatvaiAat.s1 1!j, t

NO RISK ORDER BLANK sito ,,a -tech 630 Meyer Lane, Redondo Beach, California 90278

Please send me u ith tinranr /i timmal 10-day money hack guaratl ttP:

5 Band Nova CB with house current adapter 5149.95

;] I enclose payment in full. Diner's No._ __ _

Budget terms: I enclose $40 down. Ship C.O.D.

Name ._.

Address

City, State ,;1_6




SLOPE -FRONT BOX

STOPS STOOP AND SQUINT

A small slope -front box for mounting poten- tiometers, pilot lamps, small meters, etc., at a convenient angle for reading or accessibility can be made from a small metal box. Hold and position one section of the box next to the other and move it around until you get the slant you want. Mark cut lines on both pieces, and use a hacksaw to cut away the metal that is in your way. After you file the burrs, you can mount the component on the sloping front

as shown. Jacks and other connectors can also be mounted on the box. Use self- tapping sheet metal screws to hold the two sections together. -Roger White

TROUBLESHOOT THERMAL DRIFT

WITH PLASTIC "ICE CUBES"

If you have some of those drink coolers that are made of plastic with water trapped inside, you can use them to cool off hot components when you're troubleshooting for thermal drift. The novelty plastic "ice cubes" are available in a variety of sizes and shapes, and they can snuggle right up to a sus- pected component and draw away the heat. If circuit operation is restored after the component has been cooled, you've found the defective part. -Henry R. Rosenblatt

ROTATE YOUR RADIO

FOR BETTER RECEPTION

Some of the more expensive AM portable radios on the market have antennas built


14

LOON, LISTEN! Everybody's Talkie' ... about the New Mosley '67 CB Antenna Catalog. Send for your FREE copy. Write Dept. 119.

c /1.on . SZe. 4610 N. Lindbergh Blvd. Bridgeton Mo. 63042


POPULAR ELECTRONICS



POPULAR ELECTRONICS READER SERVICE PAGE

You can get additional information promptly

concerning products advertised or mentioned

editorially in this issue

1 Circle the number on the coupon below which corresponds

to the key number at the bottom of the advertisement or is incorporated in the editorial mention that interests you.

2 Mail the coupon to the address indicated below.

3 Please use this address only for Product Service requests.

POPULAR ELECTRONICS P. O. BOX 8391

PHILADELPHIA, PA. 19101 Please send me additional information about the products whose code numbers I have circled

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75

76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100

NAME (Print clearly)

ADDRESS

CITY STATE ZIP CODE

VOID AFTER JANUARY 31, 1967 12

December, 1966 15



-

Lit

This important job rand its big salary) is reserved for a qualified

electronics technician. It can be you! It's a fact. There are thousands of jobs like this available right now for skilled electronics technicians. What's more, these men are going to be in even greater demand in the years ahead. But how about you? Where do you fit into the picture? Your opportunity will never be greater ... so act now to take advantage of it. The first step? Learn electronic fundamentals . . . develop a

practical understanding of transistors, troubleshooting techniques, pulse circuitry, micro- e!lectronics, computers and many other exciting new developments. Prepare yourself now for a job with a bright future ... unlimited

16

opportunity . . tasting security . . . and a steadily - increasing salary,.

Over 15,500 ambitious men are using Cleveland Institute Electronics Training Programs as a stepping stone to the good jobs in electronics. Why not join then? You will learn at home, in your spare time, and tuition is remarkably low. Read the important information on the facing page. Then fill out the postage -free reply card and drop it in the mail today. Without obligation we'll send you all the details. But act now ... and get your high- paving ¡ob just that much sooner.

POPULAR ELECTRONIICS



How You Can Succeed In Electronics ... Select Your Future From Five Career Programs

The "right" course for your career

Cleveland Institute offers not one, but five different and up -to -date Electronics Home Study Programs. Look them over. Pick the one that is "right" for you. Then mark your selection on the reply card and send it to us. In a few days you will have complete details ... without obligation.

1. Electronics Technology A comprehensive program covering Automation, Com- munications, Computers, In- dustrial Controls, Television, Transistors, and preparation for a 1st Class FCC License.

2. First Class FCC License If you want a 1st Class FCC ticket quickly, this streamlined program will do the trick and enable you to maintain and service all types of transmitting equipment.

3. Broadcast Engineering Here's an excellent studio engineering program which will get you a 1st Class FCC License and teach you all about Program Transmission and Broadcast Transmitters.

4. Electronic Communications Mobile Radio, Microwave, and 2nd Class FCC preparation are just a few of the topics covered in this "compact" program ... Carrier Telephony too, if you so desire.

5. Industrial Electronics & Automation This exciting program includes many important subjects such as Computers, Electronic Heating and Welding, Industrial Controls, Servomechanisms, and Solid State Devices.

140bat61.10}AtM17.

An FCC License ... or your money back!

In addition to providing you with comprehensive training in the area indicated, programs 1, 2, 3, and 4 will prepare you for a Commercial FCC License. In fact, we're so certain of their effectiveness, we make this exclusive offer:

The training programs described will prepare you for the FCC License specified. Should you fail to pass the FCC examination after completing the course, we will refund all tuition payments. You get an FCC License ... or your money back!

CIEs AUTO- PROGRAMMED lessons help TM

you learn faster and easier

Cleveland Institute uses the new programmed learning approach. Our AUTO -PROGRAM MED "lessons present facts and concepts in small, easy -to- understand bits ... reinforce them with clear explanations and examples. Students learn more thoroughly and faster through this modern, simplified method. You, too, will absorb . . .

retain ... advance at your own pace. *TRADEMARK

Lifetime job placement service for every CIE grad-

uate ... at no extra cost Once enrolled with CIE, you will get a bi- monthly listing of the many high -paying interesting jobs available with top companies throughout the country. Many Cleveland Institute students and graduates hold such jobs with leading companies like these: American Airlines, Amer-

ican Telephone and Telegraph, General Electric, Gen-

eral Telephone and Electronics, IBM, Motorola, North American Aviation, New York Central Railroad, Ray- theon, RCA and Westinghouse.

CIE lessons are always up -to -date Only CIE offers new, up -to- the -minute lessons in all of these subjects: Logical Troubleshooting, Laser Theory and Application, Microminiaturization, Single Sideband Techniques, Pulse Theory and Application, Boolean Algebra.

Full accreditation ... your assurance of

competence and integrity Cleveland Institute of Electronics is accredited by the Accrediting Commission of the National Home Study Council. You can be assured of competent electronics training by a staff of skilled electronics instructors.

NEWS FOR VETERANS: New G. I. Bill may entitle you

to Government -paid tuition for CIE courses if you had

active duty in the Armed Forces after Jan. 31, 1955. Check

box on reply card for complete information,

CIECleveland Institute of Electronics 1776 East 17th Street, Dept PE -48, Cleveland, Ohio 44114

December, 1966 19



ONE-SOURCE FOR YOUR COMPONENT NEEDS

ERIE'S EXCITING NEW ELECTRONIC

COMPONENTS STATION

...COMPONENTS IN HANDY, EASY TO

IDENTIFY PACKAGES

AT DISTRIBUTORS

Everywhere f CERAMIC DISC CAPACITORS Voltages -12 V. thru 1000 V.

Capacitance -5 pF thru 220,000 pF (.22 uF)

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MYLAR FILM CAPACITORS / Voltages -200 V. thru 600 V. Capacitance -.01 uF thru .1 uF

TRIMMER CAPACITORS (Variable)/ AreCeramic Plastic Glass Ranges to suit your needs

RECTIFIERS & DIODES Industry's Most Popular Types

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ERIE TECHNOLOGICAL PRODUCTS, INC, Attn: Distributor Sales

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NAME OF YOUR FAVORITE DISTRIBUTOR ..

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TIPS (Continued from page 14 )

into their rotatable handles so that the antenna can be positioned for best reception. You can obtain the same results with your table radio if you set it on a plastic turntable (Lazy Susan) and rotate the whole thing. These "space - saver" turntables are sold at most dime stores and department stores in a variety of sizes. Although metal turntables are more durable, you should avoid using them because they can cause interference; but select a stiff turntable to prevent the radio from shifting position with every vibration. -Art Trauffer

HANDY HOLDERS FROM FLASHBULB PLASTIC PACKING

Split plastic tubing for AG -1 flashbulbs can be used on the workbench to hold small electronic components when you're constructing

a project. They also keep resistors, capacitors and other small components in one place so that you don't have to dig through piles of assorted parts for the one you need. If you wish, you can glue a narrow strip of heavy cardboard to each tube to serve as a stand.

-George E. Gates

MAKE YOUR TRANSISTOR RADIO

A WRIST -STRAP SWINGER

If your pocket -size portable radio doesn't have a wrist strap, you're just not with it.

All you need to join the swingers are a camera wrist strap and a suitable size solder lug. Re- move the back of the radio, unsolder the earphone jack connections, and slip the jack out of its

mounting bracket. Place the solder lug over the threads, secure the jack, and resolder the wires. Then bend the lug to accommodate the strap, but leave enough room for the earphone plug. You can cut a notch in the plastic case if necessary, to prevent the solder lug from interfering with the back cover.

-S. E. Gohl

POPULAR ELECTRONICS



If You Service Citizens Radio Transceivers...

you should have AN INTERNATIONAL

C 12 FREQUENCY METER

Four Instruments In One The C -12B is more than a frequency standard - it measures power output, measures AM modulation, and is a signal generator ... all self contained in one convenient unit.

check these features!

Frequency Measurement - Range 26.965 mc to 27.255 mc. Frequency stability .0025% 32`F to 125'F; ±- .0015% 50 °F to 100 °F.

Power Measurement -0 to 5 watts, accuracy 1/a watt.

Counter Circuit - Frequency range 0 to 3 kc. Residual error 100 CPS @ zero beat.

AM Modulation Measurement - Range 0 to 100 %. Accuracy 3% @ 400 CPS @ 80% modulation.

Signal Generator - Frequency range 26.965 mc to 27.255 mc. Low output 1 microvolt through special pick -off box furnished with meter. High output 100 microvolts through output jack.

Panel Controls - Channel selector, 24 positions "Hi -Lo" frequency adjust RF level control Modulation set Power Meter calibration adjust Function selector, 7 positions Modula- tion RF Deviation Calibration Battery Test "A" Battery Test "B" Battery Test "C ".

Battery Power Required - 11/2 vdc @ 60 ma,

671/2 vdc @ 5 ma, 9 vdc.

The C -12B is capable of holding 24 crystals and comes with 23 crystals installed. Every- thing you need including connecting cable, PK box, dummy load, and batteries.

Cat. No. 620 -101 $300.00

Manufacturers of precision electronic products for home, industry and aerospace needs.

t'OS,;

WRITE FOR COMPLETE CATALOG

December, 1966

INTERNATIONAL

CRYSTAL MFG. CO., INC. to NO LEA OKLA. CITY. OKLA. 73102


21



Additional information on products covered in this section is arnilable from the manufacturers. Each new product is identified by a code n umber. To obtain further details on any of them, simply fill in and mail the coupon on page 15.

EXPERIMENTAL CIRCUIT BOARD

Want to eliminate worries about cold -solder joints, overheated devices, and burned insulation? "SPRINGBOARD," a new solderless experimental circuit hoard that permits the instant addition or removal of components without damage to leads is now in produc- 41.

. R 40.,10;,..0" . i °f tion at Barre i,.+. Instrument N. oi'ox

Corporation. 4°

The Model B I S - 1 0 0 SPRING- BOARD incorporates 120 ten -turn stainless steel springs that hold components securely and also act as connectors. All springs are electrically isolated from each other, but several can be joined with jumper wires as required by the circuit being constructed.

Circle No. 75 on Reader Service Page 15

FET FM STEREO TUNER KIT

Field- effect transistor circuitry is incorporated in H. H. Scott's LT -112B FM broadcast monitor tuner kit for maximum sensitivity (1.8 ',V) and selectivity (45 dB) with minimum cross- modulation (rejection, 90 dB) and drift. An exclusive combination front -panel meter is used initially to align the tuner, and

sf . I.

4"

can be used to indicate signal strength, zero - center tuning, or multipath distortion. All difficult -to -wire or critical circuitry in the LT- 112B is prewired, pretested, and prealigned at the factory. The kit comes with a full -color, "life- size" construction book, and with all wires precut and prestripped to the proper lengths.


22

THREE -WAY SPEAKER SYSTEM

Featured in the Olson Electronics Model S- 777 "Ultima" system is a multi -cellular midrange horn speaker for wide -angle dispersion of mid -frequency tones. A 12" woofer is coupled to the multicell horn and a 21/2" tweeter by an LC -type crossover; there are level controls on the midrange speaker and

the tweeter. The midrange horn can be turned 90` in the cabinet, permitting the cabinet to be mounted either vertically or horizontally. Power- handling capacity: up to 50 watts. Impedance: 8 ohms. Frequency response: 30 to 23,000 Hz.


AUTO SAFETY ALARM

DRIVER AWAKE! That's the name of an auto safety alarm by Executive Devices which helps to keep you awake at the wheel on long drives. Its operation is based on the fact that a driver constantly moves the steering wheel back and forth slightly no matter how straight the

highway. As the driver gets sleepy, however, the number of wheel move- ments declines. The DRIVER AWAKE stores your average rate of steering wheel move-

ments, and if it senses a deviation from the normal, it sounds a warning alarm. Moving the wheel slightly either way turns it off. The unit can be installed under the dash in less than two minutes, and it does not inter- fere in any way with steering.


PORTABLE POWER SOURCE

Most conventional portable power sources can be used for only one specific device. The lightweight, 12 -volt, rechargeable CRL -1200 "Power Pack" introduced by Centralab covers a wide range of applications and can be transferred easily from one appliance to another. It is said to power most battery- operated devices for longer periods -at lower cost -than any other power source, including the original equipment battery pack. The CRL -1200 can operate continuously up to 40 hours or more -it will power a small TV set for 10 hours on

POPULAR ELECTRONICS



Introducing EICO's New "Cortina Series "!

Today's electro- technology makes possible near -perfect stereo at moderate manufacturing cost: that's the design concept behind the new EICO "Cortina" all solid -

state stereo components. All are 100% professional, conveniently compact (31/2"1-1, 12 "W, 8 "D), in an esthetically striking "low silhouette." Yes, you can pay more for high quality stereo. But now there's no need to. The refinements will be marginal and probably inaudible. Each is $89.95 kit, $119.95 wired.

Model 3070 All- Silicon Solid -State 70 -Watt Stereo

. m.

Amplifier: Distortionless, natural sound with unrestricted bass and perfect transient response (no inter - stage or output transformers); complete input, filter and control facilities; failure -proof rugged all -silicon transistor circuitry. Model 3200 Solid -State FM /MPX Automatic Stereo Tuner: Driftless, noiseless performance; 2.4µV for 30db quieting; RF, IF, MX are pre -wired and pre -tuned on printed circuit boards - you wire only non -critical power supply.

7 New Way s to make Electronics more Fun! Save up to 50% with EICO Kits and Wired Equipment.

l You hear all the action -packed capitols of the world with the NEW EICO 711 "Space Ranger" 4 -Band Short Wave Communications Receiver -

plus ham operators, ship -to- shore, aircraft, Coast Guard, and the full AM band. 550KC to 30MC in four bands. Selective, sensitive super - het, modern printed circuit board construction. Easy, fast pinpoint tuning: illuminated slide - rule dials, logging scale; "S" meter, electrical bandspread tuning, variable BED for CW and SSS reception, automatic noise limiter. 4" speaker. Headphone jack. Kit $49.95. Wired $69.95.

Mom "ham" for your doper then c.sr - the one and only ssB /AM /CW 3 -Band Trans- ceiver Kit, new Model 753 "the best ham transceiver buy for 1966" - Radio TV Experi- menter Magazine. 200 watts PEP on 80, 40 and 20 meters. Receiver offset tuning, built -in VOX, high level dynamic PLC, silicon solid -state VFO.

Unequaled performance, features and appearance. Sensationally priced at $189.95 kit, $299.95 wired.

.!r Model 460 Wideband Direct -Coupled 5" Oscilloscope. DC -4.5mc for Color and B &W TV service and lab use. Push -

pull DC vertical amp., bal. or unbal. input. Automatic sync limiter and amp. $109.95 kit, $149.95 wired.

December, 1966

r

NEW EICO 888 Solid -State Engine Analyzer Now you can tune -up, trouble-

' shoot and test your own car or boat. Keep your car or boat engine in tip -top shape with this completely portable, self- contained, self - powered universal engine analyzer. Completely tests your total ignition /electrical system. The first time you use it - just to tune for peak performance - it'll have paid for itself. (No tune -up charges, better gas consumption, longer wear) 7 instruments in one, the EICO 888 does all these for 6V and 12V systems; 4, 6 & 8 cylinder engines.

The EICO 888 comes complete with a comprehensive Tune -up and Trouble -shooting Manual including RPM and Dwell angle for over 40 models of American and Foreign cars. The Model 888 is an outstanding value at $44.95 kit, $59.95 wired.

CRAFT New EICOCRAFT easy to -build solidstate electronic TruKits., great for beginners and sophisticates alike. As professional as the standard EICO line - only the complexity is reduced to make kit -

building faster, easier, lower cost. Features: pre -drilled copper -

plated etched printed circuit boards; finest parts; step -by -step instructions; no technical experience needed - just soldering iron and pliers. Choose from: Fire Alarm; Intercom; Burglar Alarm; Light Flasher; "Mystifier "; Siren; Code Oscillator; Metronome; Tremolo; Audio Power Amplifier; AC Power Sup- ply. From $2.50 per kit.

There's more PUNCH in the new EICO "Sentinel. Pro" 23- channel Dual Conversion 5-watt CB

Transceiver. New advanced Big -Reach "Range Plus" circuitry lengthens "talk- power" reach. Automatic noise limiter super- sensitizes for weak signals. "Finger Tip" antenna loading and transmitter tuning controls. 23 crystal -controlled transmit and receive channels - all crystals supplied. Rear -illuminated S /RF meter. Tran- sistorized 12VDC and 117VAC dual power supply. Wired only, $169.95. Positive -Negative Ground/ Mobile Marine Modification kit (optional $5.95).

FREE 1967 CATALOG PE -12

EICO Electronic Instrument Co., Inc. 131-01 39th Ave., Flushing, N. Y. 11352

Send me FREE catalog describing the full EICO line o''.

200 best buys, and name of nearest dealer. I'm inter ested in:

test equipment ham radio stereo /hi -fi Citizens Band radio automotive electronics

Name

Address

City

State L

lip

Model 232 Peak -to -Peak VTVM. A must for color or B &W TV and industrial use. 7 non -skip ranges on all 4 functions. With exclusive Uni- Probe.W $29.95 kit, $49.95 wired.




PRODUCTS (Continued from page 22)

a single charge -and as much as 40 amperes or 480 watts can be used intermittently. Charge loss during storage is only 3% per month. The CRL -1200 comes with built -in charger in a leather carrying case.


STEREO TAPE DECK

The deluxe Model RK -880 stereo record /playback tape deck introduced by Lafayette Radio Electronics incorporates features usually associated with higher priced tape decks. Three heads provide four -track stereo and mono

record/playback p l u s sound -on- sound and sound -with- sound features. In addition, the RK -880 utilizes adjustable control of playback and record equaliza- tion and bias current from

the front panel. Frequency response is 30 to 22,000 Hz at 7% in /s, ±3 dB; 40- 12,000 Hz at 3'4 in /s, ±3 dB. Wow and flutter is less than 0.15% at 7% in /s, less than 0.25% at 3% in /s. Signal -to -noise ratio: over 53 dB. The unit can be operated either horizontally or vertically.


SPEAKER SWITCHING SYSTEMS

Instant multiple -output selection of up to eight stereo speaker systems is possible with the Models 641 and 642 "Sound Control Cen- ters" announced by Switchcraft, Inc. Model 642 is designed for situations where simulta- neous distribution of sound to more than one stereo speaker system is desired; Model 641 restricts sound distribution to one stereo speaker system at a time. Frequen- cy response through the internal switching network of both units is from d.c. to 30 kHz with negligible switching loss. No external power (other than the audio power being distributed) is required for operation. Power - handling capability is 100 watts maximum into a 4 -ohm load.


AUTO "HASH HUSHERS"

"Hash Husher" kits have been developed by the Hallett Manufacturing Company to reduce the electrical interference to mobile re-

24

ceivers (hash) caused by ignition noise pulses. The kits consist of electronic RL filters that snap into place between spark plugs and leads, plus a special, filtered coil-to- distribu- tor high -tension lead. Hash Rushers fit all standard gasoline engines, won't affect mechanical or electrical operation, and can be installed in minutes.


PLASTIC LIGHT GUIDE KIT

"CROFON" light guides are now available in a do- it- yourself kit from Edmund Scientific Company. These plastic fiber optics, recently developed by DuPont, transmit light around corners, to many outlets from a single source, and into remote and inaccessible places. Used with photocells, they will count, select, detect, and sort by size, shape, and color. The Edmund kit includes two 2 -foot lengths of the light guides, one with 16 fibers, the other with 64 -which transmits four times the amount of light; concentrating lens; penlight -type light source (less batteries); and adapter for connections. It also contains all material needed to polish and cap the ends of the guides -plus detailed instructions.


IN- CIRCUIT TRANSISTOR TESTER

Rather than pulling each transistor for out - of- circuit or substitute testing, Sencore's TR- 139 lets you check any transistor or diode

without disconnecting a single lead. The TR- 139 provides two important readings: true a.c. beta, the gain factor of a transistor, and leakage current (Iao) in microamperes. In- circuit and out- of -circuit test procedures are identical. A spe- cially designed circuit in the unit protects the most delicate low - current -type transistor

or diode from damage even if the leads are accidentally hooked up backwards. And parameters of unknown transistors can be determined without a setup book or manual.


SCREWDRIVER KITS

Two new Series 99 "Plastic View" kits, each with a 111,;" x 41/8" handle and a selection of interchangeable, single -ended screwdriver blades have been introduced by Xcelite. A handy "hang -up" eyelet is provided in each compact, see -through, zipper case. Handles are of shockproof, breakproof amber plastic, and will accept any of the interchangeable screwdriver, nutdriver, and other blades in Xcelite's extensive Series 99 line. Blades are of high carbon steel with highly polished nickel- chrome finish.


POPULAR ELECTRONICS



Some plain talk from Kodak about tape:

Uninterrupted listening pleasure... and the answer to a searching question

Recoraing a pop tune or even the whole top ten isn't much of a problem with standard sound tapes. But people always want more -like getting a whole Wagnerian opus on a single reel. Actually, the problem of long playing time involves two variables: how fast you run the tape, and how much tape length you get on a reel. The following chart will give you an idea of running times with different lengths of tape:

1111111111 11111111i 21111 11/41111 ; ' -1111111111111111 ' 9iiiiiiiii°iiiiiiii

É `_.11 R' 411mÌ11

' o

7

o

1111111111111111Vi11

s,l1111 A 1111.`11 /1111PrA1111 Ci1111 S 11% 3 / %1111/ll D11!i 0G" -....11 11

i._igIN::EI111111111111 r,a11111111 w 6W IWO 1a90 IYYJ -.0

Feet of Tape

Some like it slow. Taking it slow is the obvious way to get longer playing time. This works very well up to a point. As a matter of fact, it is the historical trend -from 15

ips to 71/2 ips to 33/4 ips and so on. But as you cut speed, you make the microscopic perfection in the tape more and more important. Furthermore, at slow speeds the increased dependence upon short wavelength information and the concurrently reduced flux- carrying capacity of the tape makes head design more difficult. But even though improved quality slow -play tape recordings are strongly dependent upon improved equipment, you are still ahead with the built -in quality of KODAK Tapes -high output tape Type 34A, with its output and noise advantages, or low -print tape Type 31A.

Some like it thin. The other avenue is to go to a thinner tape . . .

one that packs more length on the reel. This too is an appealing idea -one that explains the prolifera- tion of double and triple play tapes. So what's the catch? Well, for one thing, very thin tapes re-

quire careful habits on the part of the home recordist. Your recording/ playback heads should be in good shape, as thin tape is more liable to physical distortion and breakage. Strive for smooth starts and stops. You can help by turning the reels away from one another (gently, please) so as to take up any slack in the tape which may have occurred during threading. Also, forget the fast -rewind knob - store tapes "as played." Fast rewind can set up a lot of tension and often cause erratic winding. All this can result in "stretched" or "fluted" tapes. In a nutshell, treat thin tapes with loving care.

When you record, be careful not to overload on input (if you have a VU meter, keep the needle slightly below the record level you would normally use for regular tape).

Last but not least, make sure you get your tape from a reliable maker -like Kodak. It takes a lot of extra care in winding, slitting and over -all handling to come up with a superior triple -play tape like Kodak's famed Type 12P. Because of its highly efficient oxide, Type 12P gives you a signal -to -noise ratio better by close to 6 db compared to the other leading triple - play tape. Add to this the advantage of back printing (so you always know what type of tape you're using -even when it's in the wrong box), and a dynamically balanced reel that reduces the stress and strain on a thin tape, and you can see why KODAK 12P Tape is becoming so popular.

EASTMAN KODAK COMPANY, Rochester, N.Y.

KODAK

SOUND

RECOñAG TAPE

KODAK Tapes - professional types and the long- playing variety -are available at most electronic, camera, and department stores. If you've had trouble finding them at your favorite store, Kodak would like to help. Simply tell us where you'd like to buy KODAK Tape, and we'll see what we can do about having these stores stock it. In the meantime, we'll rush you the names of nearby Kodak dealers where you'll be sure to find KODAK Tape; also, a very informative booklet Some Plain Talk from Kodak about Sound Recording Tape." Just fill out the coupon.

r -- -Mail coupon today - - --i Eastman Kodak Co., Dept. 940 Rochester, N. Y. 14650 Gentlemen: I would like to be able to get KODAK Sound Record- ing Tape at the following stores:

1) Camera store

2) Department store

3) Electronic supply store

Please send names of nearby outlets and my free copy of "Some Plain Talk from Kodak about Sound Recording Tape."

Name

Address

City & State Zip


December, 1966 25



&cd&itce

The Super -Sharp TRAM TITAN CITIZENS BAND BASE STATION *Multi -function meter reads: "S" units, SWR, and absolute power in watts into built -in dummy load. Measures power through the antenna. *Super -sharp selectivity with Collins mechanical filter- adjacent channel rejection is 90 db or better. *First class sensitivity. *All 23 transmit channels. *Transmitter delivers 3.5 watts minimum output; separate indicators for carrier on and modulation. *RF gain control. *Tone control. *Built -in low pass filter for minimum T.V.1. $434.

For full details write:

Tram Electronics, Inc. Dept. No. E -12, Lower Bay Road P.O. Box 187 Winnisquam, N. H. Phone 603 -524 -0622 All use must conform with Part 95 F.C.C. regulations. Hobby type communications or aimless small talk prohibited.

For information write directly to advertiser

ELECTRON ICS

LIBRARY DIRECT CURRENT CIRCUITS AND MEASUREMENTS

by Charles J. Anderson, Anthony Santanelli, and Fred R. Kulis

Beginner and advanced student alike will find this book a noteworthy presentation of self -instructional material designed to equip the reader with a working knowledge of d.c. circuits, using only algebra and general science. The book is organized to permit a quick reference review of important fundamentals. Readers wishing to take a refresher course are easily programmed through the text by simple notations. One of the better books in programmed self- instruction. Published by Prentice -Hall, Inc., Englewood Cliffs, N.J. 07632. 346 pages. Hard cover. $12.00.

CZ

ALLIED ELECTRONICS DATA HANDBOOK, Fifth Edition The latest edition of the Allied (Radio) Elec- tronics Data Handbook is about the most complete compact reference book on the market today -it's surprising how much information can be sandwiched into 112 pages. There is something in this handbook for everyone from the graduate engineer to the beginning student in electronics. The new edition is much larger than the last one and is chock full of specialized information as well, such as the tape recording and TV sections, to name only two. The handbook also has trigonometric tables and a cross -reference of American and foreign tubes. This book is a real time -saver and is highly recommended. Published by Allied Radio Corp., 100 North Western Ave., Chicago, Ill. 60680. 112 pages. Soft cover. 75 cents.

m CQ,

ABC's OF CAPACITORS by William F. Mullin

What is a capacitor? How is it made? Where is it used? These and many more questions you might have about capacitors are answered in refreshingly readable language in William F. Mullin's new text. Technicians, servicemen and students will find this book a valuable aid in practical applications and classroom studies. ABC's of Capacitors is designed to tear away the shroud of mystery around capacitors. Published by Howard W. Sams & Co., Inc., 4300 West 62 St., Indianapolis, Ind. 46206. 96 pages. Soft cover. $2.25. -




dme &Jo iatiet9 to(276

é liandeta,r

SOLDERING KITS for electrical soldering, household repairs, hi -fl building, hobbies and crafts

Dual heat soldering gun kit. In- cludes 100/140 watt dual heat gun with 2 trigger positions, 3 soldering tips, soldering aid, tip wrench, flux brush, solder, rugged 95 $

plastic case. Model 8200PK Si st

Heavy duty dual heat soldering gun kit. Features a 240/325 watt heavy duty gun; 3 tips for soldering, cut- ting and smoothing; tip- changing wrench; solder; break proof $

plastic case. Model D550PK l95 ist

Marksman soldering iron kit by Weller. Featherweight 25 watt iron outperforms all other irons of its size and price. Kit includes 3 different tips, soldering A44 aid and solder. Model SP23K $`thst

December, 1966

WELLER ELECTRIC CORP., Easton, Pa. WORLD LEADER CIRCLE NO. 44 ON READER SERVICE PAGE

IN SOLDERING TOOLS

27



READ WHAT THE EXPERTS SAY

ABOUT THE

knight-kit® EXPOSURE METER

HANDCRAFTED

FOR QUALITY

BY YOU i -YOUR SATISFACTION

GUARANTEED BY .4LUfD

POPULAR PHOTOGRAPHY -May, 1965 - "Any way we look at it, this kit is an excellent buy. And the lure is strong: a fine meter at far less than `readymade' cost ..." RADIO -ELECTRONICS- October, 1965 - "Wiring up some kits these days can be a major project, taking dozens of hours. This little Knight -Kit is refreshingly different - my 14- year -old daughter wired it and put it into action late one Sunday afternoon.

Most striking thing about this one is the ease of taking a reading."

Yes, the easy -to -build KNIGHT -KIT KG -275A has a taut -band two -range meter that outperforms units costing far more. Uses battery powered cadmium -sulphide photocell so sensitive you can take a reading by moonlight. Gives you correct exposure for perfect pictures -black and white or color ... movies or stills.

Complete with instructions, neck $1095 cord and batteries

Rush coupon for details and Introductory Offer r ALLIED RADIO, Knight -Kit Div. Dept. 3 -MM, P. O. Box 8528 Chicago, Illinois 60680 Please rush -free and without obligation- Special In- troductory offer on the Knight -Kit KG -275A Exposure Meter.

NAME

ADDRESS

CITY STATE


Please Print

ZIP

J

NEW

LITERATURE To obtain a copy of any of the catalogs or leaflets described belon', simply fill in and mail the coupon on page 15.

'Scott Stereo" is the title of a new 16 -page multi -color brochure published by H. H. Scott, Inc. It answers the question "What Is Stereo ?" and tells you what to look for in buying stereo components. All Scott receivers, speakers, amplifiers, and tuners are pictured and described, both factory -wired and kit units, and complete specifications are included.


Mark Products' "Heliwhip" mobile amateur band antennas with "Static Sheath" are featured in a 4 -page antenna catalog (plus in- serts). "Static Sheath" is a durable dielectric plastic covering that acts as an electrical insulator and eliminates static interference caused by the precipitation effect. A complete line of antenna mounts and accessories is also covered.


In addition to the regular line of electronic kits, Conar Instsumeats' 1966 Christmas Cata- log carries a considerably expanded line of general products, including some items just being introduced on the market. Products have been "departmentalized" and the index made more convenient. Featured are the Conar Model 800 CCTV camera, the "Audio - color," and the "300" stereo system.


Bulletin No. 94025, put out by the Clevite Corporation, outlines major reasons why ceramic filters are finding new opportunities to replace LC, quartz, and mechanical filters in military and commercial equipment. Five different kinds of ceramic filters, representative of models in production, are illustrated and described in detail.


A data sheet on Triplett Electrical Instru- ment Company's recently introduced Model 630 -APLK volt- ohm -milliammeter emphasizes its solid -state switching circuit which guards against accidental burnouts and bent pointers and provides overload protection. Other technical features and specifications are listed, and optional carrying cases and attachments are also described.




2 watts or 10o milllwatts

AM -100, 100MW transceiver. ....AM-100 personalized 6 transistor C -B unit and excellent AM broadcast radio for news, music, sports. Wonderful for football, baseball games. Hear broadcast, switch to talk with friends in stands, etc. Supplied with leather carrying case, earphone in case, crystals for Channel 11. telescoping antenna.

Complete Write for 01K-FACTS brochures on

37.50 ea.

R A Y T H E O N C O M P A N Y RAYTHEON 1 TWR-8, AM-100

... at Ray -tel the C -B portable situation is well in hand

TWR -8, full 2 watts input power, 14 transistor hand -held portable. Extra small and conveniently carried. Delivers solid signals under conditions where other units drop out. 2 channels -earphone for privacy in crowds, etc. 2 antennas: 10 section whip and 91/2" "stubby" plug -in type where clearance is low as under trees, in warehouses. Sensitive superheterodyne receiver -noise limiter -squelch. A complete big value package with 2 ni -cad batteries, battery charger, crystals for Channel 11, earphone in case, leather carrying case, 2 antennas 119.95

213 East Grand Avenue, South San Francisco, California 94080 CIRCLE NO. 48 ON READER SERVICE PAGE

New JERROLD

improves color reception three ways

1. Plus GAIN - provides sharper directivity to eliminate multipath reception.

2. Plus FLATNESS-eliminates tilts which cause incorrect colors on the TV screen. Industry experts say that color antennas must be flat within ±2 db. Paralog -Plus antennas are flat within ± 1 db per channel.

3. Plus MATCH -to prevent color- distorting phase shifts.

To give you these exclusive color features Paralog- Plus has a unique Bi Modal Director system that actually works on high and low band channels simultaneously, making each element serve double duty. What's more, you get a choice of 300 and 75 ohm coaxial outputs, plus excellent gain over the entire FM band. For the greatest realism in lifelike color, try the Paralog -Plus.

December, 1966

J1I111OIiD CIRCLE NO. 21 ON READER SERVICE PAGE

JERROLD ELECTRONICS CORPORATION DISTRIBUTOR SALES DIVISION 401 Walnut St., Phila., Pa. 19105

29



CON4 t+ ()THEN

ACEMPLED {'nODI1CT5

tytut)

The do- it- yourselfer's

newest catalog Here's your new catalog of quality electronic kits and assembled equipment ... your shop- ping guide for TV set kits, transistor radios, voltmeters, scopes, tube testers, ham gear, PA

systems, and a host of other carefully engineered products. Every item in the Conar catalog is

backed by a no- loopholes, money -back guarantee. It's not the biggest catalog, but once

you shop its pages you'll agree it's among the best. For years of pleasurable performance, for fun and pride in assembly, mail the coupon. Discover why Conar, a division of National Radio Institute, is just about the fastest growing name in the kit

CD]NJAJSS5v1 and equipment business. - --- MAIL NOW !allow= COi NA6C

3939 Wisconsin Avenue, Washington, D.C. 20016 , IlPlease send me your new catalog. , liName

111 Address ,

Zip City State Code _----- -- - - --

R2 2

G R3

CiB i0o

SOet =,

eov 1

1

OPERATION

ASSIST Through this column we try to make it possible for readers needing information on outdated, obscure, and unusual radio- electronics gear to get help from other P.E. readers. Here's how it works: Check the list below. If you can help anyone with a schematic or other information, write him directly -he'll appreciate it. If you need help, send a postcard to Operation Assist, POPULAR ELECTRONICS, One Park Avenue, New York. N.Y. 10016. Give maker's name, model number, year of manufacture. bands covered, tubes used, etc. State specifically what you want, i.e., schematic, source for parts, etc. Be sure to print or type everything legibly, including your name and address. Because we get so many inquiries, none of them can be acknowledged. POPULAR ELECTRONICS reserves the right to publish only those items not available from normal sources.

Crosley Model 616 receiver, ser. 1136823: tunes s.w. from 540 kHz to 20 MHz on 3 bands; has 6 tubes. Sche- matic :ril source for parts needed. IOW Briere. Rt. 4. Box 283. Mechanicsville. Va. 23111,

Eicor Model 400 tape recorder. ser. T 1347: has 5 tubes. Schematic and plug-in erase /record /play-back head needed. (Harold E. Reinhold. 123 S. 6 St.. N. Wales. Pa. 194541

Lettine Model 240 transmitter: covers hands from 1611

through 10 meters: has 6 tubes. Schematic. operating manual. and parts list needed. tF. J. Burgess, 1531S Deerfield. E. Detroit. Mich. 48021,

Rogers Majestic Type 20 receiver. circa 1935; tunes 145 kHz to 19 MHz on 4 bands; has 11 tubes. Schematic. alignment data. ,rod service manual needed. i Mike Thompson. 3388 E. 27 Ave.. Vancouver 12, B.C., Canadas Patterson Radio Co. Model 223 PR -10 receiver, circa 1930; tunes BC band to 15 meters: has 10 tubes. Sche- matic needed. t Arnold R. Achille. 896 Kingston St.. Aurora. Colo. 80010.

Dumont CR oscillograph. type 303. ser. .1086. circa 1950. Schematic and instruction manual needed. I Larry A. Yonkey. Rt. 2, 1759 7 Mile Rd.. Pinconning, Mich. I

Packard Bell Model 602 receiver; tunes BC; has 6 tubes. Schematic needed. ( Wayne Hellstrom. 2716 E. Melrose. Walla Walla. Wash. 99362,

BC- 721 -B /SCR -585 -B receiver. made by Galvin. Sche- matic. operating manual. and source for parts needed. IA. Tasker. 72 Belmont St.. Reading, Mass. 01867)

Crosley Model 50 receiver. Schematic and WX12 tube needed. (John Schwerbel. Rt. 1. Box 215. Catskill. N.Y.

Just -Tone Model 30417 receiver: tunes AM and FM. Schematic needed. 'Bruce Conrail. Rt. 1. Windsor. Vt. i

Johnson Service Co. Model ML -310G /AMT -1 radiosonde modulator. Molded Insulation Co. Model T -69C /AMT -1

radiosonde transmitter. Schematics and instruction manuals needed. , Richard Teh. McCallsburg, Iowa 501541

National Model SW -3 receiver and power supply, circa 193.1. Schematic -und operating manual needed. (L. Mueller, 12700 Elliott Ave., SP287, El Monte, Calif. 91731)

Sparton Model 7 -36 receiver: tunes 1.6 kHz to 18 MHz on 3 bands: has 7 tubes. Emerson Model CS -268 receiver: tunes on 2 bands: has 6 tubes. Schematics and parts lists needed. ,Carl Mason. Box 311, Rt. L Holm- del, N.J. 077331





The ideal base /mobile combination for CB radii

FOR BASE STATIONS where 117 V 60 cycle AC current is available...

The Low -Cost RCA Mark VIII and Mark NINE

9 crystal -controlled transmit and receive channels. Tunable receiver for reception of 23 C-B channels; dial marked in both channel numbers and frequency. Exceptionally good voice reproduction. Highly selective superheterodyne receiver with one RF and two IF amplifier stages. Electronic switching -no relay noise or chatter. Illuminated "working channel" feature. Light and compact -only 334 inches high, weighs only 9 pounds with mike.

Improved Automatic Noise limiter.

Plus these EXTRA features in the Mark NINE Combination "S" Meter and relative RF Output Meter (indicates the relative strength of incoming signal) and Relative RE Output Meter (indicates relative strength of signal being transmitted). Spotting Switch, Permits precise manual tuning of receiver without use of receiver crystals. External Speaker Jack. Lets you connect an external speaker to set. so that incoming calls can be heard in remote locations.

Mark VIII: $99.95*

See them at your Authorized RCA CB Radio Distributor.

Look for stores displaying this symbol.

Mark NINE: 1114.50''

FOR MOBILE UNITS where low power consumption is important...

The all -solid -state MARK 10

All silicon transistors assure low power consumption, dependable communications at temperatures from -23' to +130' F.

Compact, lightweight. Fits easily under dash of any car or truck, Only 344" high, 534" deep, 81/2" wide. Weighs less than 41/2 pounds. 12 crystal -controlled transmit and receive channels with illuminated channel selector. Combination "S" Meter and relative RE Output Meter. Operates from 12- volts DC power source (positive or nega- ti)re ground's.

Crystal -controlled double conversion, superheterodyne receiver provides frequency accuracies greater than 0.004 %. Separate AGG amplifier eliminates blasting and overloading. minimizes fading, Six -stage IF bandpass filter for maximum selectivity without ringing. Low- distortion, series -type noise limiter with automatic threshold adjustment. Receiver power regulated for maximum stability. Acoustically designed cabinet with audio characteristics shaped for maximum intelligibility. External speaker jack (de- activates internal speaker).

Mark 10: $189,95" Optional distributor resale price.

RCA ELECTRONIC COMPONENTS AND DEVICES, HARRISON, N.).

The Most Trusted Name in Electronics s CIRCLE NO. 32 ON READER SERVICE PAGE



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NAME

ADDRESS

CITY

STATE ZONE


ASSIST (Continued from page 30 )

Garod neutrodyne receiver. ser. 6000, circa 1923; has 4

tubes. Operating manual. power supply, antenna data, and source for C -301A and CX200 -A tubes needed. (Harry J. Donovan, 199 Nesbitt Terrace, Irvington, N.J. 07111)

Golden -Leutz "Super Pilotdyne" receiver, type 9, ser 140, circa, 1923; has 9 tubes. (R. Borduas, 8060 Vidal St., St. Hyacinthe, Quebec, Canada)

Grebe CR -11, CR -15, and CR -17 receivers. Schematics and /or operating manuals wanted for personal collec- tion of historical radio receivers. (J. C. Gillespie. Box 239, Park Ridge. N.J. 07656)

Stewart- Warner Model 11 -7A receiver. Schematic needed. (Jack A. Merrell. SFC NCOIC, Radio TV Repair Shop, U.S. Army, Disciplinary Barracks, Ft. Leven - worth, Kan.) Midwest Model 916 receiver, series 16; tunes AM and FM; has 16 tubes. Operating manual needed. (Mike Peterson, N. 5207 Post, Spokane, Wash.)

Supreme Model 665 composite video generator. ser. 28S. Schematic and instruction manual needed. (J. P. Maley, 95 Fairbank Ave., Toronto 10, Ont., Canada)

Hickok Model 228X crystal -controlled FM -AM signal generator. Schematic and service manual needed. (Dan- iel Gibbons. Box 84, Talara, Peru, S.A.)

REP 10D -1428 receiver, surplus, made by RCA for Royal Canadian Air Force. Schematic and service manual needed. (H. W. Baume, Box 693, Campbellford, Ont.. Canada) Stewart- Warner Model 91 -1117 receiver; has 10 tubes and magic eye. Schematic, alignment procedure, knobs. and dial holder needed. (Clyde Propst, Rt. 2, Sellers- ville, Pa. 18960)

Triplett Model 1632 signal generator, circa 1940. Op- erating manual needed. (W. Taylor, 11 Terrace Ave., Willowdale, Ont., Canada) Sparton- Withington Model 10Y21 receiver -phono combination, circa 1942; tunes AM and s.w. ; has 2 tubes and magic eye. Schematic needed. (Fred Budig, 315 E. 93 St., New York, N.Y. 10028)

Collaro Model RC54 record changer. Source for replacement needle needed. (Mark Handley, 31 Mohawk Dr., Clarendon Hills, Ill. 60514)

DeForest oscilloscope; has 4 tubes plus cathode -ray tube and 8 controls and 4 input jacks. Schematic and operating manual needed. (Henry Warchall, 4055 W. Melrose, Chicago, Ill.) RK34 tube needed. (David Hamilton, River Rd., Rt. 1,

Paw Paw, Mich. 49079)

Philco receiver, chassis P29758 ( ?), circa 1935; tunes 530 kHz to 7.4 MHz on 2 bands; has 5 tubes. Schematic and power supply filter capacitors needed. (Stanley Blair, Rt. =3. Ballston Spa, N.Y. 12020)

Atwater -Kent Model 60C receiver, circa 1929; tunes BC; has 8 tubes. Schematic, parts list, and service information needed. (Frank V. Carr, 2210 Eufaula Ave., Birm- ingham, Ala. 35208)

Radio Craftsman Model C -800 tuner- preamp. ser. H33855, circa 1953; tunes AM and FM; has 15 tubes plus tuning eye. Schematic and operating information needed. (M. Denno, 1661 Taylor St., San Mateo, Calif. 1

Sterling "B" battery eliminator, type R -81; has Ray- theon BH tube. Schematic or operating manual needed. Magnavox Model 151 B radio -phono combination; tunes AM and s.w. Schematic or service notes needed. (Brian Kennedy, 2875 Kenmore PI., Santa Barbara, Calif. 93105)

Harvey -Wells Model "Bandmaster Deluxe" 50D transmitter, circa 1950; tunes 3.5 to 144 MHz on 8 bands. Schematic, operating manual, and VFO needed. (G. F. Huffines, 2073 Ahneita Dr., Pleasant Hill, Calif.) Emerson Model OP- 8QS -509A receiver; tunes 550 kHz to 18 MHz on 2 bands; has 6 tubes. Dial cord information needed. Atwater Kent amplifier, type TA; has 2

audio stages. Schematic, battery and receiver connection information needed. (Chuck Ridenour, Rt. 1, Box 408, London, Ohio 43140)

Rocket Model 8HL TV receiver, macle by Egawa Elec- tric Lab Co. Inc. of Tokyo, Japan. High- voltage transformer ZC105726 needed. (E. J. Bunker, 1804 Thorn - bury Rd., Baltimore, Md. 212091


POPULAR ELECTRONICS



Even if you've never had a slide rule in your hands before

...you can now start solving electronics problems fast with this new electronics slide rule and course

EVER ENVIED the way some fellows whip out a "slip stick" to solve a problem... instead of struggling

through it with pad and pencil? Now you can "outshine" them -even if you've never

used a slide rule before. With our exclusive new Electronics Slide Rule, you can

do not only common mathematical calculations but also special electronics problems in resonance and reactance.

This is a professional slide rule in every detail, made for us by Pickett, Inc. It has two special scales for solving resonant frequency and inductive or capacitive reactance problems -or any problem involving the factor 27r. On the other side... a unique decimal point locator plus useful electronics formulas and conversion factors. Handsome leather carrying case has heavy -duty plastic liner, removable belt loop, flip -open cover.

With it you get four full -length AUTO -PROGRAM MED TM

lessons which teach you with actual examples how to use it. These lessons are carefully designed to meet the same high educational standards as our famous electronics career courses. Each lesson will be personally graded, if you wish, by one of our expert instructors the same day it is received and returned with his comments.

To make friends with career -minded electronics men, we have deliberately underpriced the CIE Slide Rule and Course. The low cost will really surprise you.

Find out more. Send for free booklet. No obligation, of course. Mail coupon or write Dept. PE -127 at the address below.

CIE Cleveland Institute of Electronics 1776 East 17th Street, Cleveland, Ohio 44114

CIRCLE NO. 7 ON READER S December, 1966

Acclaimed by Electronics Experts "It opens a whole new era of quick calculations. Even if you never had a slide rule in your hands before, the four -lesson instruction course that is included takes you by the hand and leads you from simple calculations right through resonance and reactance problems with hardly a hitch."

-WAYNE LEMONS, Radio- Electronics "Why didn't someone think of this before ?...the slide rule saved me time the very first day. The 'refresher' course is a marvel of clarity. I couldn't help being amazed at how many standard formula functions I was performing the hard way." -OLIVER P. FERRELL, Editor, Popular Electronics "I was very intrigued by the 'quickie' electronics problem solutions. It is an ingenious technique. The special scales should be of decided value to any technician or engineer."

-JOSEPH J. DeFRANCE, Head of Electrical Technology Dept., New York City Community College

Mail this coupon for FREE BOOKLET

How to Solve Electronics Problems in Seconds

With new Electronics Slide Ele and Ind aII , r

Cleveland Institute of Electronics 1776 East 17th Street. Cleveland. Ohio 44114 Please send me without charge or obligation your booklet describing the CIE Electronics Slide Rule and Instruction Course. ALSO FREE if I act at once: a handy pocket -size Electronics Data Guide.

Name (please print)

Address

City State Zip Accredited Member National Home Study Council A Leader in Electronics Training ...Since 1934.

PE -127

ERVICE PAGE 33



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37



ASSIST ( Continued from page 32)

Millen secondary frequency standard, type 90501, ser. 1151. Schematic and service manual needed. (Harry M. Hammond, 1095 Arlington Ave., Teaneck, N.J. 07666)

CFT -46154 receiver, made by Federal Radio Telegraph Co. Parts list and operating manual needed. CRV -20130 power supply, used with CFT- 46154, macle by RCA. Schematic and manual needed. (Robert H. French, 450 38 St., Bellaire, Ohio 43906)

Hallicrafters Model S -22 -R receiver. Output transformer needed. i Richard Harris, Box 284, Camilla, Ga.) Atwater -Kent Model 55C receiver; has 7 tubes. Operat- ing manual, parts source, and celluloid tuning dial and cabinet needed. (James Chew, 900 N. 4 St., Jeannette, Pa. 15644) Atwater -Kent Model 33 receiver. Sockets and coils needed. Atwater -Kent Model 20, Two audio transformers with 3 hole mounts needed. (J. N. Clapp, 1516 Elm St., Davenport, Iowa 52803) Firestone Model R -316 -A receiver, ser. 116047; tunes s.w. Schematic and tube complement information needed. (Wayne Aho, 13 Memorial St., Balclwinville, Mass. 01436) F.M. Link Model 1905 receiver; has 13 tubes. Schematic and alignment information needed. (R. Leon Bridwell, Box 176, Antlers, Okla. 74523)

Millen syncroscope, type CJA- 60ACM, surplus. Con- version diagram needed. (Fred Jahn, 1675 Oriole St., San Leandro, Calif. 94578) B & K Models 500 & 550 tube testers. Tube checker adapters needed. (Bill T. Brinson, 608 N. Shartel, Oklahoma City, Okla. 73102)

Atwater -Kent Model 44 receiver; has 8 tubes. Source for tubes needed. (Dave Beal, 501 Pleasant Hill Ct., Rt. 1, Duluth, Ga.) Hickok Model 530 -B tube tester, circa 1939. Instruction manual needed. (R. L. Trott, 1690 Sharkey St., Talla- hassee, Fla. 32304)

Cossor Model 1 -035 oscilloscope, circa 1954. Schematic and operating manual needed. (J. F. Rich, 94 Neilson Dr., Etobicoke, Ont., Canada) Creative Electronics Model "Transcon 10" transmitter and converter, circa 1957. Schematic and operating manual needed. (Dick Hutchinson, 1705 Kaywin Ave., Bethlehem, Pa. 18018)

Motorola Model PA- 8343 -A receiver; tunes FM from 152 to 174 MHz. Source for parts needed. (G. D. Griffin. 322 W. State St., Ithaca, N.Y. 14850)

CW -50124 demodulator, surplus, circa 1948. Operating manual and tube source needed. (Gery Sasko, Box 552, Rt. 1, Monongahela, Pa. 15063)

Weidenhoff Model 1004 ohm -capacity meter, ser. 5994. Schematic, operating and alignment information needled. (Michael Sidey, 427 Grace Ave., Garfield, N.J. 07026)

Superior Model 670 -P VOM. McMurdo -Silver Model 900 "Vomax" VTVM. Schematics needed. (R. S. Davey, Box 58, Frankfort, Ind. 46041)

Superior Model TW11 tube tester. Tube chart roll needed. Feiler Model T59 VTVM. Schematic needed. (Leo Pencok, 10678 St. Charles Rd., Sumner, Mich. Grunow Model 1291 receiver, chassis 12B; tunes 550 kHz to 18 MHz on 2 bands; has 12 tubes. Schematic needed. (Robert McDaniel, 711 4 St., Fairbury, Nebr.) Zenith Model 55 -29 receiver, ser. N225899; tunes 550 kHz to 18 MHz. Motorola TV receiver, chassis 27E90129, circa 1948; has 14 tubes. Schematics needed. (Joe Rock, Jr., Box 162, Knoxville, Md. 21758) Gonset "Communicator II" transceiver, ser. CM 7357. Hallicrafters Model S -38D receiver, ser. F 129310. Operating manuals needed. (James Lincoln, 12 Crest- view Terrace, Wallingford, Conn. 06492) Airline Model 14BR904A receiver; tunes on 5 bands; has 10 tubes. Schematic and operating manual needed. ¡Mike Timmons, 14200 S.W. 184 St., Miami, Fla.) Electronic Research Associates Model 50TM power supply. Schematic and operating manual needed. (Thomas McCarthy, 367 Bergen Blvd., Oradell, N.J.)


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CIRCLE NO. 22 ON READER SERVICE PAGE 38 POPULAR ELECTRONICS



Looking for Hi -Fi equipment, but in the dark about which to buy? Well you can always .. . {l :

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December, 1966

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40 CIRCLE NO. 4 ON READER SERVICE PAGE POPULAR ELECTRONICS



COVER STORY

SCIENCE FAIR

PROJECT

USING INTEGRATED CIRCUITS (IC'S),

THE DEMONSTRATOR DUPLICATES THE LOGIC FUNCTIONS OF GIANT ELECTRONIC COMPUTERS

By DON LANCASTER

EVER wondered how is it that electronic computers are able to exhibit

such a distinctively human characteristic as making logical decisions? Ask the "Logic Demon" and it will tell you that, very simply, the answer lies in the truth of logic- computer logic.

And what IS logic? It is the process of determining, by deductive reasoning, the means of obtaining a desired result from a given set of conditions, Consider the following paradoxical dialogue involving formal logic which dates brick to Aristotle:

Socrates: "What Plato is about to say is false."

Plato: "Socrates has just spoken the truth."

Now, if Socrates spoke the truth, then Plato's statement must be false. But if Plato's statement is false, then Socrates

did not speak the truth and, hence, what Plato said must have been true. If Plato spoke the truth, then Socrates also spoke the truth, and hence what Plato said is false. Needless to say, this circular process could go on and on. But can this formal logic be reasoned out mathe- matically?

The Logic Demon, utilizing the latest in resistor -transistor logic í RTL l circuitry, can serve as a demonstrator/ trainer in computer logic --the same logic used by the giant sophisticated digital computers. And you can build the Logic Demon for under $10 to show off at your next Science Fair.

Computer Logic. Computer logic, also known as Boolean Algebra. translates Aristotle's formal logic to a mathematical logic which can be used for reasoning

December, 1966 41



out problems. Developed by Augustos De Moran and George Boole over 100 years ago, Boolean Algebra (computer logic) was crystalized in 1938 by Claude E. Shannon who, while studying for his Master of Science degree at M. I. T., applied it to the solution of switching problems.

As an example of Shannon's application of computer logic to solve practical problems, consider the simple series circuit shown in Fig. 1. Two switches (A and B) are in series with lamp 1 and a battery. If you ask which switch must be closed in order for current to flow and light the lamp, the answer would be that both switches -A AND B -must be closed. Thus, the circuit is called an AND gate. A gating circuit is one that operates as a switch to apply or eliminate a signal.

Following a logical procedure, a table can be made listing all possible switch combinations to prove that switches A and B must be closed at the same time or current will not flow. Thus, Switch "A" Switch "B" Lamp "I"

Closed Closed Lights No No No No Yes No

Yes No No Yes Yes Yes

As shown in the table, a "yes" appears in the lamp column only when a "yes" appears in both switch columns. The table can be simplified by substitut- ing a "0" (zero) for a "no" and a "1" for a "yes." This allows us to establish a convention to symbolize that a statement or condition is false when a 0 is represented, while a 1 can be used to denote that a statement or condition is true. The simplified table is as follows:

Switch "A" Switch "B" Lamp "I" Closed Closed Lights

0 o o 0 1 o 1 0 o 1 1 1

In computer logic ( also called symbolic logic) , the preceding table is known as a truth table for the logical AND for it represents the simple true statement that the lamp lights only when both A AND B are closed at the same time.

If the same switches are rearranged and connected in parallel as shown in Fig. 2, the following table can be pre-

42

=BATTERY

SWITCH SWITCH

Fig. 1. Switches A and B in series with a battery and lamp can represent the logical AND circuit.

SWITCH A

1 SWITCH

BATTERY B LAMP I

Fig. 2. In the logical OR circuit, current flows if either switch A or switch B, or both, are closed.

SWITCH

A N.0 .0

T

- +- OPEN .1

CURRENT FLOW BJ SWITCH

A CURRENT

B

o

o

Fig. 3. In this circuit, the lamp lights when A is NOT pushed; the circuit is called a NOT gate.

SWITCH

A N.C.

BATTERY

T

SWITCH 6 N.0

LAMPA

Fig. 4. A NOR gate is represented by adding one or more switches to the NOT gate described above.

F. 5. The NAND function can be depicted by nor mally closed parallel -connected switches A and B.

POPULAR ELECTRONICS



pared to show for what switch combination the lamp will light: Switch "A" Switch "B" Lamp "I"

Closed Closed Lights 0 0 0 0 1 1

1 0 1

1 i 1

The lamp lights when either one or both of the switches are closed. Thus, logically, I is 1 (true) whenever A OR B (OR A and B) is true (closed) , and the circuit is called a logical OR gate.

Consider the circuit of Fig. 3. Unac- tuated, normally closed (NC) switch A represents a 0, but when pressed, the switch represents a 1. The correspond- ing truth table asserts that B (current flow) is 1 whenever A is 0, and that B is 0 whenever A is 1. In other words, the lamp lights (is 0) when the switch is NOT pushed, and is extinguished when the switch is pushed (1) . The circuit is characterized by a single switch, and is called a NOT gate (inverter).

By adding one or more switches to the NOT circuit, we come up with what is called a NOR gate (Fig. 4) . A truth table for this circuit would state simply that C (current through the lamp) is true only if both A and B are false, and that C is false if either A or B is true. Since these conditions represent the opposite (negative) of the OR -NOT OR -it is called simply a NOR gate.

The opposite (NOT) of the AND gate can be represented by the circuit of Fig. 5. The NOT AND, or briefly, NAND, function can be depicted by the normally closed parallel- connected switches (A and B) . The lamp lights if either or both switches are left in their "0" position. But it will be extinguished if both switches are "1" (pressed) at once.

Applying Computer Logic. A computer is capable of carrying out a long string of YES -NO decisions without having to repeatedly ask for more information as the operation progresses.

Depending on the complexity of the problem to be solved, thousands upon thousands of such decisions, may be needed for mathematical problems requiring addition, subtraction, multipli- cation, and division. Programmed instructions, stored in the computer's memory, coordinate all operations, time

(A)

(B)

Fig. 6. NOT operation can be performed by a one - input RTL gate shown in (A). A two -input gate (B) can serve either as NOR or NAND circuit.

them for proper sequence, and route the information in the proper sequence to the various registers and output devices.

Logic gates can be constructed with such devices as relays, switches, tubes, and transistors. But in this era of microminiaturization, integrated circuits (IC's) offer the greatest advantage because they occupy very little space, con- sume little power, are extremely reliable, are quick- acting, and inexpensive.

Of the many varieties of logic IC's on the open market, the resistor -transistor logic (RTL) variety is probably the most popular. It can easily drive other

INPUT A

INPUT B

+3V

OUTPUT

Fig. 7. The AND function is obtained by the addition of a NOT gate to output of a NAND gate.

December, 1966 43



IC's, and operates with voltage levels that are compatible with the requirements of external circuits. Typical one - and two -input RTL gates are shown in Fig. 6. If additional inputs are required, more transistors are added.

Operation of the gates is simple. If a transistor receives an input, it turns on

PARTS LIST

B1 -1.5 -volt size "D" flashlight c, /l 21 11-3.2-volt, 160 -mA pilot light I ( , E #1490 or

similar) IC1- Fairchild 11L914 epoxy Micrologic dual

two -input gate (Data sheet and list of distributors available from: Fairchild Semiconductor, 313 Fairchild Dr., Mountain View, Calif.)

Q1- Motorola MPS 834 transistor, or 2N834, or similar type (Data sheet and list of distributors available from Motorola Semiconductor, Box 955, Phoenix, Ariz. 85001)

S1, S2- S.p.d.t. switch or two -circuit NO /NC push -button switch

S3-4 -pole, 5- position non -shorting selector switch (similar to Mallory 1325L)

1 -5" x 4" x 3" cabinet (similar to Bud CU- 2105A or Premier PMC -1005) 1- Metalphoto dialplate (optional)* 1- Sealectro TS -800 IC 8 -pin socket (available from Federated Purchasers, Inc., or Arrow Elec- tronics, Inc., both in New York City)

Misc.- Battery holder, bracket for QI (optional -see text), bar -type knob, 5 /16 " -i.d. rubber grommet, transistor socket for Q1, nylon or rubber feet with hardware (4), rivets or screws for battery holder

*Available from Reill's Photo Finishing, 4627 N. 11 St., Phoenix, Ariz. 85014: in silver color -$2.75; blue, red, or copper -$3.25; postpaid in the C.S.A.

to produce 0 output at the collector. The one -input gate, shown in Fig. 6(a), is the NOT circuit. If +3 volts are applied to the input, the output becomes O.

The absence of a voltage at the input produces +3 volts at the output. Ob- serve that the output is always opposite in state to the input.

Now consider the two -input gate shown in Fig. 6( b) . By first establishing that the presence of +3 volts at the input represents a 1, and the absence of this voltage represents a zero, the gate will function as a NOR gate since a 1 at either input produces a 0 at the output. If an OR gate is desired, a NOT circuit (one -input gate) can be added to the output to reverse the state.

If, on the other hand, it is established that the presence of +3 volts at the input represents a 0, while the absence of this voltage represents a 1, then the circuit will function as a NAND gate so long as the +3 volts appears on both inputs. Once again, the adding of a NOT circuit reverses the function to produce an AND response. See Fig. 7.

We can now proceed to build the "Logic Demon" around the circuits discussed so far by including a suitable selector switch and a transistor lamp-

N.0

NOR

S3A

OR

OFF*

AND

TNAND

1

-9S3Cj

+ 3VDC

I

o MPSe34

Fig. 8. Through exclusive use of dual two -input gate elements, any logic function can be generated from basic NAND /NOR gates in a fully integrated monolithic circuit.

BI

-2'D'"CELLS _T_




TO SUIT INSULATED MOUNTING TERMINALS FOR 01

ALUMINUM I REQUIRED

13/32 DRILL

Fig. 9. Mounting bracket for Q1 made from a thin piece of 3/4" x 2" aluminum plate. See text.

driver stage. After designing and building the Logic Demon, it can be used to perform real computer logic operations.

About the Circuit. The "brain" of the Logic Demon is integrated circuit ICl which contains dual RTL two -input gates (Fig. 8) . One input is eliminated from one of the gates by grounding pin 3. Thus, a two -input gate and a one - input gate remain.

When the output (which drives Q1) is taken directly from the two -input gate, the circuit performs the NOR /AND functions. However, by feeding the output of the first gate to the one -input gate (which acts as an inverter or NOT gate) and then taking the output from the latter gate, the OR and NAND functions are obtained.

S2

SI

S3

01

MTG. BRACKET

The Logic Demon can be wired using the schematic diagram and component layout shown in this photo.

A selector switch defines the input logic states and routes the lamp- driving transistor (Q1) to the appropriate gate output. If desired, separate slide or toggle switches can be used to produce the same logic functions.

Construction. The unit can be assembled on a metal chassis or in a wooden or plastic container. However, the use of a 5" x 4" x 3" metal box will give the project a neat appearance.

Except for the two dry cells which are mounted in battery holders that can be pop- riveted or screwed to the base, the switches, IC, and indicator lamp are mounted on the enclosure cover. If you use the prefabricated dialplate (see Parts List), the appearance of the project will be enhanced, and the dialplate can also serve as a drilling template for the holes that must be made in the cover to accommodate the switches, lamp, and the IC. The mounting hardware for the switches can be used to hold down the dialplate on the cover.

The IC shown here is mounted on individual Teflon insulated feedthrough connectors, but an alternate -and better -method is to use a single 8 -pin Press - Fit IC socket as specified in the Parts List. Pin 8 of the IC case is usually coded with a red dot, or it may simply be beside the flat side of the case. Viewed from the top of the case, the pins are counted counterclockwise.

Transistor Q1 is mounted on stand -off insulators inserted in a fabricated aluminum bracket (Fig. 9) which is secured on the inside of the enclosure cover by the rotary switch. However, this mounting procedure need not be followed since Q1 can be mounted on a transistor socket in any convenient location in the enclosure.

The pilot lamp fits in a 5/16 " -i.d. rubber grommet that mounts in a hole through the dialplate, and leads are soldered directly to the bulb. After making all the wiring connections (Fig. 8), you can proceed to test the unit.

Operation. If the unit is wired correct- ly, it will obey all the logic rules indicated on the dialplate. With the switch in the NOR position, the bulb lights and is extinguished by pressing either push


December, 1966 45



The "Scrounge" an Instant "J" Antenna

YOU CAN WHIP A VHF ANTENNA TOGETHER IN 30 MINUTES

THE "J" style antenna has been around for years and years. Hams, police,

forestry and fire radio stations started using the "J" back in the 1930's, and even today it is not uncommon to see a Business Radio system using "J" antennas. The advantages of the "J" are the omnidirectional characteristic of the radiated pattern and the vertical polari- zation -two important requirements in working mobile and vertically polarized stations. The short wavelengths of the very high frequencies also favor the use of these vertical antennas.

CUT AWAY SHADED PORTION

ENTIRE PIECE 30011TWINLEAD

1/2 WAVELENGTH (INCHES). 5540

fMHz

1/4 WAVELENGTH (INCHES). 2420

iMHz

1 OUTER CONDUCTOR

CENTER CONDUCTOR

500. COAX, ANY LENGTH

This simple antenna can be fashioned from a single length of 300-ohm twin lead.

46

By ALBERT S. VON TROTT, W3UIX /6

If you are going on 6 or 2 meters, you will probably find the vertically polarized antenna a welcome addition to your antenna farm. Also, if you are an SWL tuning for the radio services between 150 and 170 MHz, the "J" antenna will be a practical and valuable asset.

You can build a "J" antenna from a short length of 300 -ohm twin lead à la "Sneaky Pete" in just about 30 minutes. A very desirable feature of the "J" antenna is the built -in quarter -wave matching section which lets you use a regular 52 -ohm coax transmission line ; VSWR's of less than 1.3 :1 are not unusual.

The drawing shows the simple layout of the "Scrounge" with notations for determining its length. If you are working a band of frequencies, cut the antenna to resonate in the center of the band. If you are interested in listening on 156 MHz, for example, simply divide the figure 5540 by 156 to determine the length of the half -wave section (351/2 ") . This is the radiating portion of the "J." Add to this dimension the length of the quarter -wave matching section ( 2420 156 - 15.5) to find the total length (approx. 51 ") . The higher the frequency, the shorter the antenna.

The rest is simple. Cut one conductor 351/2" from the end of a 51" piece of 300 -ohm twin lead and remove it. You can use a knife to cut the insulation, or you can strip out the undesired lead by getting a good grip on the cut end and pulling. Don't try it with your fingers or your teeth; use a pair of diagonals or pliers.

Tape your "Scrounge" to a wooden pole, solder the wires at the bottom of the "J" to your coax feed line, and you're in business.


POPULAR ELECTRONICS



SINGLE BATTERY -OPERATED 2- TRANSISTOR DIPPER

SPANS 3 TO 30 MHZ ON 5 BANDS

EDO operates on a small 9 -volt battery. By ROBERT N. TELLEFSEN Its frequency range is continuously vari-

able from 3 MHz to 30 MHz, and -for suitable bandspread -is divided into five different bands. A sensitivity control and more than adequate current flow lets you start with a full -scale reading on all bands. Inexpensive home -brew plug -in coils are used, and the entire project costs about $15 to build.

ONE OF THE MOST useful instruments a ham, CB'er, or experiment-

er can own is a Grid Dip Oscillator (GDO) . The GDO is a versatile instrument which makes the job of finding the resonant frequency of an unknown tuned circuit a snap, as well as detect- ing oscillations, tuning and neutralizing transmitters, finding unknown values of coils and capacitors, and performing a host of other tests.

The Emitter Dipper (EDO) does all the things a GDO does, but unlike the GDO's with their a.c. line cords, the

How It Works. The Emitter Dipper has two simple transistor circuits: a Colpitts oscillator (QI) , and an emitter - follower (Q2). Variable capacitor Cl provides the EDO with a VFO capability, and any frequency within range can be quickly obtained. Frequency of oscillation is determined by the value of the plug -in coil (Li) and the setting of CI (see Fig. 1) . Capacitors C2 and C3 form the feedback network to sustain oscillation. Capacitor C.r, mounted in four of the five plug -in coils, helps estab-

December, 1966 47



L I* C2 OpF.

CI C3 50 30

I

\\pF. pF.

*SEE COIL TABLE

01 2N711A

Fig. 1. Signal generated by the Q1 Colpitts oscillator circuit drives Q2. Meter reading dips when an external circuit absorbs a part of the signal.

RI

I.IK

lop F.

R2 RS 2.4K 27K

C4 .001).1F.

lish the proper level of feedback for each frequency range.

The r.f. signal from the oscillator is coupled to Q2. The meter across R4 serves as an emitter current indicator. Variable potentiometer R.ç is used as a sensitivity control and is adjusted to obtain a full -scale meter reading when the plug -in coil is operating in the "clear."

When the coil is held close to a tuned circuit and the EDO is operating at the resonant frequency of the tuned circuit, some of the r.f. energy is absorbed by the tuned circuit. Amount of absorp-

FLAT SURFACE

02

BI 9V

SI

tion depends on the degree of coupling. The resultant drop in signal strength from the Q1 oscillator circuit shows up as a decrease in emitter current, and causes the meter pointer to dip. The meter reading will be maximum above and below the resonant frequency.

Construction. Except for the plug -in coils, all components are mounted inside a 4" x 21i" x 21-11" metal box. Parts layout is not critical. Drill appropriate - size holes in the cabinet to accommodate the meter, jack, and other components. You can follow the layout shown in Fig.

Fig. 2. Parts layout is not critical, but avoid excess component lead length. Strap the battery firmly in place to prevent short circuits.

LI J1 C2 R3 R2 R1 C4 C1 81 RFCI 02 C7 51 R4

01 Ce

48

Fig. 3. Wind all coils as shown, and in accordance with the Coil Table. Four of the five coils require a small capacitor (Cx).

POPULAR ELECTRONICS



PARTS LIST

B1 -9 -volt transistor battery C1 -50 -pF variable capacitor (Hammarlund

HF -50) C2, C6 -10 -pF disc capacitor C3 -30 -pF disc capacitor C4- 0.001 -µF disc capacitor C5- 0.7 -11F, 10 -volt disc capacitor C7- 0.005 -µF disc capacitor Cx -See Coil Table 11 -5 -pin miniature socket (.l mphcnol 78 -SSS) L1 -See Coil Table M1 -0 to 1.0 -mA meter Q1- 2N711A transistor, or similar Q2- 2N2924 transistor, or similar R1- 1100 -ohm, 4 -watt resistor R2- 2400 -ohm, % -watt resistor R3- 27,000 -ohm, '; -watt resistor R4- 10,000 -ohms potentiometer, linear taper

(Mallory U -20 Midgetrol) RFC1- 2.5 -mH choke, 25 to 50 mA coil (Millen

or Mallory) S1- Add -ozz s.p.s.t. switch for R4 (Mallory

US -26) 1 -2 %" x 2/4" x 4" metal box Misc.-3-lug terminal strip, center lug mounting;

3 -lug terminal strips, end -lug ',muzzling (2); pointer knobs (2); sheet metal or plastic strip, nuts and screws

L1 COIL TABLE

NUMBER OF TURNS

WIRE SIZE*

VALUE OF Cx

FREQUENCY RANGE (MHz)

471/2

321/2

171/2

121/2

61/2

#28 #24 #24 #16 #16

470 pF

470 pF

100 pF

100 pF

none

3 to 4.4 4.4 to 7.6 7.4 to 11.6 11.5 to 18 18 to 30

*Enamel- coated solid conductor

Fig. 4. Dial markings should be made when you cali- brate your EDO. Align the knob pointer horizontally when C6 is fully meshed, and tighten knob in shaft. Photo shows actual size of dial scale on prototype.

2. You may have to modify a terminal strip to fit, but that is easily accomplished with a pair of cutters.

A 1" x 4" piece of sheet metal or plastic strap holds the battery in place. If you wire S/ into the circuit at the point marked "X" instead of between the battery and ground, as shown in the schematic, you can connect the negative side of the battery directly to ground.

Wind the coils on 3/4 "- diameter poly- styrene plug -in forms according to the information given in the Coil Table. See Fig. 3. Don't use a different wire size or make any other changes in the coil winding data if you want to obtain the indicated tuning range. Before soldering any of the pins, heat -sink them to prevent melting the coil form.

You can make a 21/4" -diameter circular dial out of a piece of heavy paper or cardboard. Draw three concentric circles on the dial, :;io" apart, starting ?" from the outer edge. The frequency range and intermediate points of the five plug -in coils can then be marked on these circles, without crowding. To mount the dial on the cabinet, cut a 1 /, "- diameter hole in the center of the dial, remove the hex -nut from the shaft of Cl, center and paste the dial over the opening, and replace the nut. Mount the knob securely on the shaft, and cali- brate the dial. See Fig. 4.

Calibration. Accuracy of the EDO can be no better than the accuracy of your calibration procedure, or the calibration equipment you are working with. An accurately calibrated receiver or a crystal - controlled generator can be used.

If you are working with a receiver, turn on the receiver's BFO, plug in the 3 -MHz to 4.4 -MHz coil switch on the EDO and place the coil end close to the receiver's antenna. Tune the receiver to 3 MHz, rotate C/ until you hear a tone in the receiver, and mark the EDO dial. (Tune for zero beat.) Advance the receiver's tuning in 100 -kHz steps, advance Cl, and mark the dial as you go. Do the same for the other coils.

Mark a different semicircle on the dial for each plug -in coil. It makes no difference which half of the dial you use. Mark the dial just like a ruler (short and long marks) with numerical call - outs at 1 -MHz positions. -C30-

December, 1966 49



By J. W. NELLIGAN

COMPREHENSIVE ADULT EDUCATION COURSE COVERS PRACTICALLY EVERY

PHASE OF TAPE RECORDING

THE IMPACT on one community of an idea that struck Lon Cooper, an

electronics jobber in St. Petersburg, Florida, has set into motion currents of energy that may have significance for tape recording enthusiasts everywhere. Lon was reading a brochure sent out by the Pinellas County (Fla.) Board of Public Instruction. As he glanced over the listing of all the courses offered by the adult education department, he thought, "Why not a class in tape recording techniques ?"

Cooper's long career in electronics and his reputation as an authority on magnetic recording would qualify him for certification as a part -time instructor. So, a few days later. Lon met with school

officials and presented his idea to them. The educators were impressed with

his reasoning that: "Probably no single piece of electronic equipment available today has greater usefulness or can provide more entertainment than the tape recorder. It has infinite applications in school, in business, and in recrea- tional activities."

"Okay," they said, "If we can enroll a minimum of ten students, we'll schedule a class."

The new course was officially called "The Tape Recorder -Its Use and Care." Within a few days after it was announced in a local newspaper, 20 students had enrolled. Then registration reached 25 -the maximum permitted. Eventually, Cooper was compelled to start a waiting list and schedule another class.

Who enrolled? A teen -ager and an 80- year -old retired engineer were among the first to pay the established $2 fee. Then there were several audiophiles, and a former star of the Chicago Opera Company who intended to record pro- fessionally. But most of the enrollees were just people with a yen for tape recording who wanted to learn more about it.

Cooper's new class had neither prece- dent to follow nor a published text avail-




Unique course in recording techniques was conceived by Lon Cooper, shown at far left demonstrating fundamentals of sound. In the "lab,"

(above), students record from various sources and practice programming.

able. In preparing the curriculum, he had to rely largely upon his own knowledge supplemented by material from such books as Tape Recorders How They Work, by Wescott and Dubbe, and Mag- netic Recording for the Hobbyist by Arthur Zuckerman. But others came forward with assistance. For example, Audio Devices, Inc., a pioneer in the development of quality recording tape, furnished much of the material used in sessions on recording tape.

Audio -visual equipment was also made available -an overhead projector proved to be indispensible during lecture periods. Other equipment included a combination signal generator- amplifier -speaker- oscilloscope arrangement used to demonstrate audio principles.

Starting with the history of magnetic recording, the course touches on the fundamentals of sound, treats the students to a small dose of theory, and continues logically through transport mechanisms, motors, recording indicators, bias oscillators, heads, amplifiers and speakers, recording tape and microphones. In the "lab," students learn head alignment, investigate testing procedures, record from various sources, and practice programming including mixing, editing, and splicing.

The class makes three field trips: (1) to a local church which uses magnetic recording ; (2) to Radio Station WLCY to watch program taping; and (3) to the sound room of the Cooper Radio Company, where the students are instructed in the proper use of connectors and cable hookups, and are given an opportunity to use tape recorders in con- junction with other types of audio equipment.

Finally, the class receives instruction in the methods of evaluating tape recorders, tape, and accessories. The students learn to read "specs," are told what to look for in choosing a tape recorder and are cautioned against "bargain basement" tape.

At this writing, three classes have been graduated in St. Petersburg, and a fourth is in progress. In addition, plans have been completed for an advanced class.

But of special significance to tape recording enthusiasts outside the St. Petersburg area is the interest shown in these classes by Superscope, Inc., marketing agency for Sony tape recorders. Superscope is exploring the possi- bilities of making Lon Cooper's course available to all amateur tapers -wherever they may live. --

December, 1966 51



SMALL TAPE RECORDERS

MALL TAPE recorders can be used for entertainment, private -eye work,

correspondence, conference recording, dictation, voice training, and can be made to perform many other practical - and many not so practical- functions. They do have certain limitations, but their portability, low price, and ability to work -after a fashion -under the most adverse conditions, make them highly desirable.

What can be done with a small tape recorder depends upon its features and usually its cost. Some small machines record and play back only at "one" speed, accommodate only small 21,2 -inch reels, work only on batteries and cost as little as $10. Some $35 recorders operate on 117 -volt, a.c. power, at two speeds (1"iß in /s and 33/+ in /s) , and accommodate larger reels. Some have a switch on the microphone for remote control, and some have outlets for extension speakers and earphones.

Capstan or Direct Drive. When shop- ping for an inexpensive tape recorder, be aware of the fact that not all recorders drive the tape in the same man- ner, and that tapes recorded on one machine cannot always be played back properly on another machine. Two methods in general use are capstan drive and direct drive.

Capstan drive offers a greater degree of uniformity of tape speed. It rotates at a predetermined fixed speed, such as

in /s or 331 in /s, and draws all the tape through the recorder at the same rate of speed regardless of the size of the reels or the amount of tape on the reels. Tapes recorded on a capstan drive recorder can be played back on another capstan drive recorder providing that the tape speed is the same and the geom- etry of the recorded sound track is compatible with the playback heads.

MAN WAS MADE FOR BETTER

THINGS TO DO- LET THE TAPE RECORDER

HELP YOU GET

GREATER PRODUCTIVITY AND MORE LEISURE

By HERB HOWORKA, Jr.

In a direct -drive recorder, the take - up reel is the driving element and it revolves at a set speed, but actual tape speed varies constantly. Beginning tape speed could be at the rate of about 1 inches per revolution, depending upon the diameter of the reel's hub, and end- ing tape speed greater than 9 inches per revolution on a 3 -inch reel.

When a direct -drive recorded tape is played back on a capstan -drive recorder, the first part sounds like a flock of monkeys; somewhere toward the middle of the tape, the sounds become intelli- gible; and near the end, the sounds become a series of grunts and growls.

In a great many instances, tapes recorded on a direct -drive tape recorder must be played back on the same recorder, or on another machine of the same make and model. Forget about splicing a section of tape recorded at the beginning of one reel into the middle or end of a tape on another reel.

Mike Fright. With a small recorder, you can tape all sorts of interesting "people talk" -when the people are relaxed and speak freely. However, if you put a microphone in front of some people, they "clam up." Try hiding the recorder and





SMALL. BATTERY -OPERATED TAPE RECORDERS HAVE BEEN GREAT- LY IMPROVED WITHIN THE PAST TWO OR THREE YEARS, AND QUALITY UNITS ARE AVAILABLE AT REASONABLE PRICES. PRICES FOR THE UNITS SHOWN HERE RANGE FROM $39.95 TO $79.50.

RCA "YHS12" 3 -inch reel, 2 tracks; 2 speeds (33/4 and 1 7/8 in /s); operates on 4 "C" cells

for 20 to 40 hours intermittently and 10 hours continuously; can be remotely controlled;

93/4" x 91/4" x 23/4 "; 4.9 lb.

December, 1966

Norelco "Continental 101" 4 -inch reel; 2 tracks; 17/8 in /s speed; operates on 6 "D" cells for 40 hours; has combination audio level and

battery condition indicator, and can be remotely controlled; 8" x 11" x 33/4 "; 7 lb.

Sony "Sony -Matic 907" 31/4 -inch reel; 1

track; 2 speeds (33/4 and 17/8 in /s); operates on 4 "D" cells for 20 hours; has automatic record level circuit (a.v.c.), and can be remotely controlled; 83/4" x 83/4" x 51/2"; 51/2 lb.

Craig "212" 31/4 -inch reel; 2 tracks; 2 speeds (33/4 and 17/8 in /s); operates on 6 "C" cells; has automatic level control and fast wind and rewind; can be remotely controlled; 77/8" x 93%" x 31/4"; 41/2 lb.

53



TRANSISTORS are wonderful devices for the experimentally- minded elec-

tronics hobbyist. They are small and easy to work with, the power supply requirements are absolutely minimal, and the associated components are usually standard items. All sorts of transistorized circuits can be whipped together in a few hours, checked out, and put in operating order if you use a "breadboard" similar to the one shown here.

Construction. The base for your breadboard can be a 12" x 12" x 1" piece of white pine. Varnish or shellac the board for the sake of improved appearance. Lay out screw holes according to the diagram and make spring terminals from short lengths of 3/,"-diameter door

SPRING TERMINALS

+- COI + -+- + i

I

+---C®c -+--+---+- BM® +---+- -¡-

±---IllWE -+---t--+ I

I

+ -c® -+----+- -+ I

This arrangement will 1, 2, or 3 transistors

54'1 ,.,

t 5/8"

enable experimentation with in control or audio circuits.

SOLDERLESS

BREADBOARD CUT UP A SCREEN DOOR RETURN SPRING AND MAKE YOUR OWN QUICK- CONNECT TERMINALS

By A. A. MANGIERI

spring -the kind used to close a sum- mertime screen door. Make each spring length about 12 turns and bend the last turn at a right angle to form an eye for a wood screw.

Screw the terminals to the board using small wood screws and flat metal washers. Face the "base" connections for your transistors to the left and all other springs to the right. Twenty -three springs is about right for nominal small - scale experimenting with transistors. You can add assorted brackets of %%is"

aluminum to support volume controls, inductors, tuning capacitors, etc., as required.

Using the Breadboard. The preferred method of using a breadboard is to lay out the circuit according to the arrangement in the schematic. Practically every transistorized circuit schematic reads from left to right, and the transistors are positioned so that the collector is toward the top of the board and the emitter toward the bottom. Use the top row of springs for the collectors and the bottom row for the emitters. Of course, the springs can be loosened and rotated to face any direction.

Miniature transformers fit between transistor terminal groups; larger transformers are mounted at the top of the board. Transistors with short clipped leads will require sockets; to solve this problem, solder some leads to a "universal" transistor socket and attach the socket to the board and the leads to the appropriate springs.

To install or remove a component from the spring terminals, simply push the blade of a small screwdriver into the coil and slip wire lead in or out. -30




"Relaxatrol" to Automate

Your Slide Projector VARIABLE TIMER CONVERTS PUSH -BUTTON

MACHINES TO FULLY AUTOMATIC OPERATION By GARY W. TOWNER

LOOK. NO HANDS- here's a low -cost way to fully automate a push- button

semi -automatic slide projector. Build a "Relaxatrol," set the speed of operation, and join the audience. It is an ideal accessory for continuous repeat- perfor- mance applications.

Actually, the Relaxatrol can be used to automatically control at preselected intervals almost any device which is operated manually with switches -without modifying the equipment. The only re- quirement is that the control be hooked across the switch on the equipment. The control can be overtaken or "dropped out" of the equipment at any time without any additional connections or dis- connections.

How It Works. A simple relaxation oscillator consisting of Rl, R2, C2, and Il (Fig. 1) periodically energizes K1 to trigger the projector. Capacitor C2 takes on a charge through R1 and R2, until the voltage across it is sufficient to fire II (usually on the order of 60 to 70 volts).

When the lamp fires, it discharges C2 until the voltage drops sufficiently to black out the lamp. The frequency of lamp ignition depends upon the values of C2, RI and R2, as well as the voltage across the entire circuit. Variable resistor R2 makes it possible for you to adjust the frequency according to your needs.

Neon lamp 11 is close -coupled to a December, 1966 55



Fig. 1. When PC1 "sees" the light from Il, its resistance drops and lets enough current flow to energize Kl. Time constant of R1, R2, and C2, as well as the applied voltage, determines the frequency of operation.

light -dependent resistor (PC1) . When the lamp lights, PC1's resistance drops and allows enough current to flow through Kl to energize it. In the absence of light, the combined resistance of R3 and PC1 is enough to keep the relay in its off position. The relay simply does what the slide- change push button on the projector would normally do, if the relay contacts are wired in parallel with the push button.

A bridge rectifier can be made up of four individual diodes, but you may find

PARTS LIST

C1 -8 -9F, 150 -t.olt electrolytic capacitor C2- 16 -9F, 150 -volt electrolytic capacitor Li-A-E -2 neon lamp K1- 10,000 -ohm, 4.5 -mA relay (Allied Radio

75 U 774, type LB -5 or similar) PC1- LDR -C1 light -dependent resistor (Allied

Radio 7 U 565, or similar) PLI -2- terminal plug (small size; use with

matching socket) R1- 2.2- megohm, % -watt resistor, - 10% R2- 10- megohm linear potentiometer R3- 4700 -ohm, z -watt resistor, ± 10% RECT -1- Rectifier bridge (International Recti-

fier 10DB3A, or similar) S1- S.p.s.t., 6- ampere switch Misc. -Black alligator clip insulator, 2%" x 4"

x 1 9/16" plastic case, 2- terminal strips (4), line cord, hookup wire, knob, etc.

Ki R2 C2 RI

I17 VAC

it more convenient to use the commercially available module described in the Parts List. Capacitor Cl serves as a power supply filter.

Construction. Layout is not critical and it may be possible to assemble all the parts inside your projector. If you do, be sure to keep the parts away from

TEST PROBE INSULATOR

I7 PCI PLI REGT I 0

Fig. 2. Parts layout is not critical. Small plastic box helps insulate relay and other components from a.c. line. A Iine cord can be substituted for PL1.

56

Fig. 3. Black insulator fitted over PC1 and 11 permits assembly to function without interference from external lighting.

the hot lamp. However, in most instances, it is better to build a separate unit.

The small plastic meter box shown in Fig. 2 is inexpensive, easy to work with, and looks good. A test probe insulator. the kind usually placed over an alligator clip, couples the light from the neon lamp to PC1 and shields the assembly from "outside" light. (See Fig. 3.) You may cut away some of the insulator at each end if it is too long. Assemble the unit as shown in the drawing, and do your best to obtain a light -tight assem-


POPULAR ELECTRONICS



WANT TO BUILD AN INTEGRATED

CIRCUIT

BINARY

COUNTER?

By DON LANCASTER

COUNTING IN THE BINARY SYSTEM IS SIMPLE: YOU START WITH "ZERO, ONE" ... AND YOU'VE

USED UP ALL OF THE BINARY DIGITS

NOW you can build a demonstration binary counter using inexpensive

integrated circuit (IC) industrial flip - flops with ordinary pilot lamps serving as readout devices. The binary counter described on the following pages can be used to demonstrate basic digital computer principles including the addition of binary digits. It also provides an opportunity to utilize integrated circuits for storing binary information.

In order to use the binary counter, however, you must understand the concepts of binary arithmetic. Most of us are familiar with the decimal number system which needs just 10 symbols -digits 1 through 9, and 0 -to express any

December, 1966

quantity. And while some earlier computers did use this system for comput- ing, the complexity of the circuits dic- tated the need for a simpler system, one requiring fewer digits. So a number system using two digits only -1 and 0- was devised : the binary ( base -2) number system.

Binary Number System. To learn how the binary (base -2) system works, consider Fig. 1 in which four groups of blocks are shown. The first one -block on the right is preceded by a group containing two blocks, which is preceded by a group containing four blocks, preceded by an eight -block group.

57



Fig. 1. Counting in the binary system is easy. To build binary 13 requires one 8- block, one 4-

block, no 2- block, and one 1- block; thus, 1101.

Now, since we are working with a base -2 number system, we could change things a bit by writing the same group of blocks in this order: 23, 2 -, 2', 2 °.

The superscript numerals (3, 2, 1, and 0) are referred to as the powers of the base number which, in this case, is 2. The power of a base tells the number of times the base must be multiplied by itself or, putting it another way, the power to which it is raised. For example, 2' - 2 x 2 x 2 - 8. The mathe- maticians tell us that a number raised to its 0 power is 1; thus, 2" becomes 1. But we can also write: 8, 4, 2, 1 to represent the blocks.

To express 3 in the binary system, we need no 8 block, no 4 block, one 2 block, and one 1 block. In binary notation this is written as 0011. Similarly, the number 10 is written as 1010. And that is all there is to the binary number system.

The convenience of this system is immediately apparent, considering that any number in the decimal system can be converted to a series of l's and 0's. Thus, to "write" a number on a punched card, you either have a hole or no hole -a 1 or a 0. Putting it another way,

Fig. 2. This four -stage flip -flop has a counting limit of 15. Adding stages increases count capacity.


a YES or a NO. If lights are used as a readout device, it could be established that if the lamp lights it means a 1, and if it doesn't, it means a 0.

Binary Addition. Adding 5 and 3 gives us 8 in the binary system just as it does in the decimal system, except that the numerical process is different. The following decimal -to- binary conversion table will save you some time in working out a few examples of binary addition.

DECIMAL NUMBER

BINARY NUMBER

0 000 1 001 2 010 3 011 4 100 5 101 6 110 7 111 8 1000

Three basic rules govern binary addition: (1) 0 plus 0 equals 0; (2) 1 plus 0 equals 1; and (3) 1 plus 1 equals 0 with a 1 carry to the next left -hand column. Applying these rules to the sample problem 5 + 3 will give you

COUNT PULSES



NOTE. ALL LAMP DRIVER RESISTORS SHOULD BE 47011 EXCEPT LAST STAGE IN COUNTING CHAIN

+3VDC

01

RI 470

I2

02

22

03

I3

MPS834 MPS834

R2 47011

R3 IK

SEE NOTE

TO STAGE 4

USED)

PULSE SHAPER

N.C. SI S2

0.

CLEAR

COUNT

Fig. 3. Binary counter schematic shows three very low cost flip -flops (IC1, IC2, and IC3), a pulse shaper (IC4) and digital readout lamps.

OFF ON

53 - B1 - 3VDC

IC µL914 IDENTIFICATION

1 -Gate A, Input 1

2 -Gate A, Input 2 3 -Gate B, Input 1

4- Common 5 -Gate B, Input 2 6 -Gate B, Output 7 -Gate A, Output 8 -Vcc + 3 Volts D.C.

IC 4923 IDENTIFICATION

1 -Set Input (Gnd.) 2 -Count Input 3 -Reset Input (Gnd.) 4- Common 5 -Not used 6 -Clear Input 7- Output 8 -Vcc + 3 Volts D.C.

PARTS LIST

B1 -1.5 -volt, C -size cells (2) 11, 12, 13 -#49 pilot light (2.0 -volt, 60 -mA) ICI, 1C2, IC3- -14L923 epoxy J1í flip -flop (Fair-

child *) IC4 -11L914 dual two -input gate (Fairchild *) Q1, Q2, Q3 -2N834 transistor (Motorola

MPS834) R1, R2- 470 -ohm, 3/4 -watt resistor R3- 1000 -ohm, V4-watt resistor -sec text Sl- S.p.d.t. push -button switch S2- S.p.s.t. push -button switch S3- S.p.s.t. slide switch 1 -6" x 4%" x 1j," aluminum box with cover

(Zero Z64- 104A -20 and Z64 -1044- COT -5) or 5" x 7" x 2" box chassis (Bud AC -402) I- METALPHOTO dial plate, hard anodized aluminum, with POPULAR ELECTRONICS trademark, available irom Refill's Photo Finishing, 4627 N. 11 St., Phoenix, Ariz.

85014; in .ssl.'sr color for $2.75; blue, red, or copper for $3.25; postpaid in U.S.

1 -2" x 3" sheet of aluminum or perforated phenolic board

1-1V8"-diameter aluminum disc (optional -see text) 4- Sealectro S -lead IC sockets for TO -5 case (optional. available from Arrow Electronics

or Joseph Kurzan, !nt., both in New Pok City)

Misc.- Teflon insulated terminals (52, optional), insulated feedthroughs (4, optional); battery holder for two C -size cells, % " -o.d. rubber grommets (3), pop rivets or #6 hardware, 6 -32 .- Y8' threaded spacers (4), rubber feet (4), wire, solder, #6 mounting screws (4)

*Data sheets and distributor list available from Fairchild Semiconductors, 313 Fairchild Dr., Mountain 1'dcv, Calif.

101 + 011 -1ó0ó

To define the above addition, starting with the right -hand column you have

1 + 1 = 0 with a carry of 1. Place the carry above the second column so that it now contains 1, 0, and 1. Thus, the second column is also 0 with a 1 carry. The carry added to the third column also produces a 0 with a 1 carry. Since there

December, 1966 59



RIVET 4 6-32 X 3/8 THREADED

SPACERS HERE

I/2° DRILL 15)-.

r-5/8-1-5

I-1/2"

I/8bRILL(8)

2 -3/4"

F9/16" 9/16%-1

3 -1/2"

Fig. 4. You can use these dimensions to duplicate the front cover layout. Hole sizes should be made to accommodate your hardware and fittings.

6 -1/2 I.D.

4' I.D.

IF NAMEPLATE IS USED RECESS ALL I /B" HOLES

AS SHOWN

is no fourth column in the problem, the carry is brought down as the fourth or most significant digit of the sum. The answer then becomes 1000 or 8.

When adding more than two binary numbers to produce a single sum, the numbers should be added in pairs. In other words, the sum of the first two numbers is added to the third number. The fourth number is then added and so forth until the last number is added to the sum of the previous two numbers to produce the total sum.

Electronic Counters. The essential difference between an electronic counter and earlier counters with mechanical wheels is that the electronic counters add pulses instead of gear teeth. But in addition to its ability to add, a counter must also have a way of storing the discrete digits representing the numbers.

A decimal counter, for example, must be able to store ten counts -0 through 9- before the next count resets the

60

II

02 01

RI

ICI

S2

Fig. 5. The flip -flop IC's, and transistors and resistors, are first mounted on a subassembly supported on standoff spacers. 1C4, shown on an aluminum disc, is supported by the push -button COUNT switch (S1).

IC2 S3

12 I3

03

R2 R3

IC3

IC4 SI (HIDDEN)

POPULAR ELECTRONICS



1C4 COUNTER

SUBASSEMBLY BATTERIES

STANDOFF DIAL SPACERS PLATE

(4)

RUBBER GROMMET

counter to 0 with a 1 carry. Similarly, a binary counter is required to store only two counts -1 and 0- before it is reset. The electronic circuit used for counting is a simple flip -flop with its "set" state representing a 1, and its "reset" representing a 0.

The block diagram of a four -stage flip - flop binary counter that provides a count of up to 15 is shown in Fig. 2. Addition- al stages can be added to increase the count limits. For example, if one more stage is added, the count is increased to 31, while adding two more stages increases the count to 63.

During operation, pulses are applied to the count input of the l's stage. A carry output from this stage is passed on to the count input of the 2's stage, and so on down the line to the last stage. With each incoming pulse, the l's counter is alternately set to one, then reset to 0, set to 1 again, and so on.

The 2's counter also alternates between 1 and 0 each time it receives a count, but this happens only during every other input pulse when the l's counter develops a carry signal. This process continues to activate each counter up to the last pulse in the string.

The IC Counter. Figure 3 shows the schematic of the IC counter. The in- nards of IC1 -4 have been deliberately left out to simplify matters. IC1, 1C2, and 1C3 are the counting flip -flops, while IC4 is a medium -power dual two -input resistor -transistor logic gate serving as a pulse shaper to eliminate the effects of contact bounce when the COUNT push button (Si) is pressed to produce the count pulses.

The modified output from the pulse shaper is applied to the count input of first counter stage ICI. The output of ¡Cl is applied to the count input of IC2, whose output in turn is applied to IC3. Indicator lamps I1 through 13, driven by Ql through Q3, visually de-

"POP "RIVET OR #6 HARDWARE

Fig. 6. This cutaway view of the front cover shows how the subassembly is mounted on the spacers. Observe that the mounting screw holes are recessed a bit so the dialplate can lay flat on the cover assembly.

note the presence or absence of a 1 in each counting circuit. When a flip -flop circuit goes into its 1 state, a positive voltage is applied to the base of its respective output transistor through the proper base resistor (R1, R2 or R3) . The voltage causes the transistor to conduct, lighting the lamp.

Observe that R3 is of a larger value than either RI or R2. If it were not so, lamp 13 would burn brighter than Il and 12 since IC3's output is not loaded by the input of any other flip -flop, as is the case with ¡Cl and IC2. Thus, if additional counting stages are added, bear in mind that the larger base resistor must appear in the last stage, although the base resistor of the other stages are of equal value.

CLEAR switch S2 provides immediate reset capabilities by simultaneously applying a "1" pulse to the CLEAR input of each counter, resetting it to the 0 state.

Construction. The binary counter can be assembled in any small metal, wood, or plastic container. It is shown assembled in a 6" x 41 /9" x 11/4" aluminum box. A prefabricated METALPHOTO dialplate (see Parts List) can be put on the container cover to give the project a professional appearance. Layout and dimensions for drilling the cover are shown in Fig. 4. You can, however, lay out the counter differently, if you wish, since neither parts arrangement nor lead dress will affect operation of the unit.

Use a low -wattage soldering iron when assembling the unit to minimize the possibility of overheating and destroying the transistors and IC's. For ease of assembly, the IC's and transistor circuitry can be preassembled on a 2" x 3" aluminum plate, or phenolic circuit board. Then the plate or circuit board can be mounted on standoffs in the container cover. Interconnection is made from the


December, 1966 61



ALL ON QUARTER -INCH MYLAR SOME COMMENTARIES ON THE

TAPE RECORDING SCENE

By AL JOHNS

no (in

"I bug offices ... what do you do for a living ?"

1

Qgo EKX1

onr) nC1

.. and this device will eliminate your flutter and WOW!"



How to Conduct an Interview With a Tape Recorder* NO MORE PENCILS,

NO MORE PAD,

NO MORE MISQUOTES TO MAKE YOU MAD

ARE YOU an attentive listener? Do you enjoy relaxed and easy conver-

sation, and can you pose interesting and intelligent questions? If these qualities describe you, and you own a tape recorder, you have the makings for a fascinating hobby or another source of income.

Unlike the old BTR (Before Tape Re- corder) days when an interviewer barely had time to get a few questions answered because of the limitations of pencil and pad, modern interviewers are able to capture 100% of all that is said. Freedom from note -taking lets the interviewer concentrate fully on the subject matter and maintain complete control of the proceedings.

*Much of the material in this story also applies to office conferences such as the one attended bp staff members of POPULAR ELECTRONICS in photo above. Note automatic Concord Model .350 battery - operated recorder in background.

By LEWIS A. HARLOW

Almost any standard medium -sized tape recorder in reasonably good condition can be used to record an interview. The recorder should accept a 5 -inch tape reel and be easy to carry.

Omnidirectional microphones are perhaps the best to use for a large group because they can pick up sounds coming from all directions. However, the microphone supplied with your recorder is usually quite suitable for interviews.

If you have a choice, avoid recording with a hand -held microphone. The main disadvantage of the hand -held mike is the constant fluctuation of mouth -to- mike distances which produce variations in volume and pitch.

The best microphone position for most indoor recording is near the center of the room with the mike pointed away from the window to minimize back-

December, 1966 63



ground noise. Prepare an extension cable for your microphone so that the tape recorder can be tucked away in a corner where it won't attract attention during the interview.

Round out your equipment with a good supply of empty tape reels, an editing kit, and an ample supply of tapes. Select your tapes carefully and don't let the "look- alike" appearances fool you. Tapes vary in quality and price and there could be an enormous difference in footage among tapes for any given size reel. If your primary interest is to get maximum playing time from a reel of tape, select a thin tape, such as 0.5 mil. A 7 -inch reel of 0.5 mil tape, played at a speed of 33'4 inches per second, will give over two hours of unattended playing time per track -ample enough for most interviews.

A relaxed atmosphere is a must for interviews. Before you attempt to set up your first appointment, practice with your family and friends until you build up your confidence. Also, invest in one of the many paperback books which ex- plain the mechanics of interviewing. Professionals usually jot down key questions on a small card (3" X 5" )

which can be held in the palm of the hand and glanced at without distracting the person being interviewed.

Basic to all interviews is the require- ment that you know as much as possible about the story you are after. It also helps to know a little about the background of the person you plan to interview. If he is a public figure, newspaper files can usually provide you with all the information you need to have about his career. Most people are impressed when someone takes the time and effort to learn about them. To be sure, the best way to inspire confidence is to first start out by praising the achievements of your subject.

Half the battle is won with the proper placement and handling of your microphone. If possible, use a stand mike which permits easier control of mike -to- subject distance and eliminates finger - tapping noises that are invariably produced by hand -held mikes. The mike should be placed on a table approximately equidistant from each person involved in the interview. Experiment to

determine an appropriate distance and the required recording level for the room acoustics.

After preparing the room and setting up your recorder and mike, all you should have to do is flip the record switch to be "on the air." Once the interview is started, keep it going in a normal con- versational tone.

Look directly at the person being interviewed, and by no means keep looking at the mike. The line of questioning should not lead to "yes" or "no" replies, but rather to a "here's my point of view" dialogue. If the person being interviewed wanders off on an unrelated track, act interested, and don't interrupt him. You can always edit the tape later.

If you are shown clippings or other prized possessions, read them into the microphone, and return them immediately. Also, any off- the -record comments should be kept confidential. By all means, when you edit the interview, destroy these passages. Your integrity must never be questioned.

Let the tape recorder run without your attention and do not stop the recorder with every pause. When the tape runs out and you can hear it flapping, show some concern, but make it appear that it would pain you if some important point in the interview were missed.

When the interview is over, you will know it because there will be nothing more to talk about. Thank the person you interviewed for taking so much of his or her valuable time, and pack up.

Editing the interview tape can be a time -consuming yet rewarding experience. All unrelated material and pauses which produce blank tape should be spliced out. This is where the empty reels come into play.

Identify the deleted tape you want to keep with written captions, and wind it on a separate reel. You can even rear- range the dialogue so that it follows a plausible, continuous line of thought.

The edited tape should play smoothly from start to finish without any apparent jumps or "blips." If your first attempt is not wholly successful, don't be discouraged. As you become more experienced, your taped interviews will take on a more professional quality. HA-




sHur par ,o00,1? A NGELO / bON'r l.er IT 01/rol

THE cLOsErl

EIGHT MINUTES

LATER

roue TOOT/WOW

s/N TfIk"LYlNL80Y,

EIGHT MINUTES

LATER

EIGHT MINUTES

LATER

PARLOR GAME By LEWIS A. HARLOW

IF THAT OLD hidden microphone gag has just about worn thin at your so-

cial get -togethers, why not pull a switcheroo? It's a lot more fun to do, and it can be a bigger party perker -upper than those replays.

Prerecord about 90 minutes worth of tape with pauses between attention -getting phrases spoken a little louder than normal conversation. About eight minutes of pause is the limit if you want to keep your guests' attention. Don't make it too short, though, or you'll lose the whole effect.

EIGHT MINUTES

LATER

rN12rY ,SEVEN ry/RrY S'EYEV riaRr SEVEN ._ . ,

Shown above and below are examples of the type of dialogue you can use. Tailor your dialogue to fit the company you plan to have over.

When the guests have begun to gather into small groups for the inevitable small talk, mute your hi -fi and start the tape going. Allow an initial eight minutes of blank running time so that anyone who might have seen you turn the recorder on will have forgotten it.

When the dialogue starts, watch the party perk up and the small talk turn to a discussion of your switcheroo. -{3-

EIGHT MINUTES

LATER

11SMELLS TOME LIKE

P1,4577c.

EIGHT MINUTES

LATER

rAfis ROPE iSAJ'T

LONGE/00ff. GETMt

A SHOVEL .

/Ve- or ro co 11044E

NOW. pLEASE 3HUT

ME OFF,/



A TAPE RECORDER NIT

DELUXE NEW HEATHKIT AD -16 PUTS TOP -QUALITY FOUR -TRACK TAPE RECORDER IN THE HI -FI STEREO BIG LEAGUES

THE FELLOW at the Heath Company who thought up the idea of putting

someone else's accepted manufactured product into a kit deserves a pat on the back. Heath introduced this new phi- losophy a few years ago with a couple of electronic organs ( Thomas) . A 21" color TV kit followed which looked suspicious- ly like an RCA, and a few months ago Heath announced a deluxe tape recorder kit that is really the Magnecord 1020 in kit guise.

POPULAR ELECTRONICS built one of the first of the new Model AD -16 recorders and can .eport that the Heath /Mag- necord marriage is a happy one. Within 1714 hours, the AD -16 was assembled and ready for tape head alignment. Another hour, and the recorder was mounted and playing as perfectly as any hi -fi enthu- siast might desire.

Why Build a Tape Recorder? There are three important reasons to start you on your way to building an AD -16. First, there is a significant monetary saving. The AD -16 is selling as the Magnecord 1020 for 45' more than you pay for the

kit. Since 16 -18 hours of construction time is about average, you're getting a bonus equal to $10 per hour for your spare time.

Secondly, the AD -16 cum 1020 is the Rolls -Royce of the tape recording industry. This IS a deluxe tape recorder -all solid -state circuitry (21 transistors) and ready for instant operation (no warmup). Third -and this is important -when you build a piece of gear like a tape recorder, you learn. You learn how the whole recorder operates; you learn the mechanics of the transport; and when maintenance is required, you have the experience and a manual with all the facts right at your fingertips.

No Need To Be a Mechanic. If you have ever opened up a tape recorder and been startled by the maze of flywheels, linkages, drive belts and cams, you can be excused for thinking that building a


First step in building the AD-16 tape recorder is wiring the power supply circuit board (left), which takes about 2 hours. Next in line is the major printed circuit board (below), with the remainder of the electronics. The average builder should reach this point in about 8 to 9 hours of working time.



SHORT SPECS

Two -speed (71/2 and 33% in /s), 4 -track recorc and playback, with provision for sound-on sound or sound -with -sound recording.

The AD -16 accepts 1/4"-wide tape; 1.5, 1.0. 0.75, or 0.5 -mil thickness. Use 7" NAB reels or special 81/4" Magnecord reels.

Measured frequency response at 71/2 in/s exceeded 45- 17,500 kHz at ± 2 dB.

Unit draws 140 watts maximum, measures 13%2" x 175 /e" x 81/4 ". Price: $399.50. Base, $19.95, extra.

Mounting the two electronics assemblies on the main frame also involves mounting the power transformer, filter capacitors and bleeder resistors. By the time your AD -16 looks like the photo, below, work time will be just under 12 hours. Another 3 hours is spent assembling the transport mechanism (below, right). After the heads are mounted, the recorder will look something like the rear view photo at right, in just about 171/2 hours. The small inset panel is for connections to the tape auxiliary input, monitoring, and tape output. The silver knobs are for winding up the a.c. power cable. Microphone and headphone jacks are all on front panel.

Except for external coloration, the Heathkit AD -16 has the physical appearance of a Magne - cord 1020, at a price saving of about $175.00.



ZERO-BEATING THE NEWS

TOM THUMB WEATHER STATION -With its state -of- the -art accuracy in

measuring basic weather variables, the AN /TMQ -22 Meteorological Measuring

Set made for the U.S. Army by Cambridge Systems, Inc., is said to be the

most advanced portable weather unit to go into the field to date. One man

can set it up in less than 5 minutes.

HOT STATIC COOLER- Tremendous heat and tiny particles in rocket

exhausts often produce communications -

blanketing static. This giant octagonal ring, developed by Lockheed

Propulsion, is used to study these effects in an effort to design rockets that do not generate static.

68

"REHABAPHONE" -Among the unusual equipment designed by General Telephone

and Electronics Corp. are dials in Braille for the blind, telephones

that answer themselves for the paralyzed, and telephones in oversized

booths at convenient heights for wheelchair patients. Shown above is the "Rehabaphone" which requires only a slight pressure on a switch for dialing.

POPULAR ELECTRONICS



WORLD'S LIRGEST -The largest Meatf>< r radar E ¡stem ever to be placed

aboard a stip s i-stalled on the "P.yDfu -kfaru. ' The system was designed

and built for :he Japanese Ministry of T-a by Toshiba, and is

inc)rporates rr _ny new features, one of which is a device :ha: maintains

desire] antennE angle ccmpensating for pitch ng and rolling in heavy seas.

MULTIPLEXED TEACHER -Educasting Systems, Inc., has developed a new

method by which educational programs are multiplexed on one regular

FM or CATV channel. Four separate supersonic subchannels which

correspond to the choices of answers make it possible for the student

to press one of the four buttons on a

special Sylvania -built receiver to indicate his answer. If a wrong answer

is selected, the correct answer is given plus the reasoning behind it.

SATURN SANDWICH TO GO -The more than 60 component parts which make

up an Instrument Unit are assembled and hung inside 3' -thick slices of a

Saturn rocket. The slices are fitted between the propulsion stage and

the payload. The Instrument Unit will guide a Saturn vehicle

on a suborbital flight. IBM engineers and technicians check the slices

out prior to delivery to Cape Kennedy.

! 1s!:-_

Decesnb-r, 196E 69



SCIENCE FAIR

PROJECT

TESLA'S

THERMOMAGNETIC

MOTOR A LITTLE -KNOWN

INVENTION BY

THAT CONTROVERSIAL GENIUS

By ARTHUR S. COOKFAIR

MENTION Nikola Tesla to any electronics hobbyist and the chances

are his first thought will be of the Tesla Coil. Upon reflection, he may recall that Tesla had something to do with developing alternating current power transmission, or the invention of the induction motor. lh^ fact is that in the early days of electricity and magnetism, Tesla's active mind was probing in many directions to find ways of putting these forces to use. The thermomagnetic motor was one approach.

Unlike the induction motor (Tesla's most useful contribution) , the thermomagnetic motor was destined to obscu- rity. It is a little known invention buried among the millions of inventions in the archives of the U.S. Patent Office. The motor itself is easy to construct and

provides a simple -yet interesting-sci - ence fair project or demonstration device to show the effects of temperature on magnetism.

Theory. Tesla's thermomagnetic invention is based on the phenomenon known as Curie temperature (after its discoverer, Pierre Curie -of radium fame) . The Curie temperature is the point at which permanent magnetic properties of certain metals go down the drain.

A Curie temperature transformation occurs in both hard and soft magnetic materials. Hard magnetic materials - such as alnico or hard steel -are those which are used in the manufacture of permanent magnets. Soft magnetic materials, such as soft iron, are those metals which are easily magnetized when placed in a magnetic field, but tend to lose their magnetism rapidly when removed from the field. Since permanent magnets can be damaged by excessive heat, Tesla's thermomagnetic motor was designed so that heat would be applied only to a soft magnetic material.

The Curie temperature varies for different metals. Iron loses its magnetism at 770° C, nickel at 360° C, and cobalt




The above sequence shows how Tesla's motor operates. As the gas flame heats the nickel, a point is reached when the attraction to the alnico magnet is

cancelled. A weak spring pulls the arm and nickel away from the flame. When the nickel cools, the magnetic attraction is restored and the nickel

returns to its original position. This oscillation should be at a rate of about 20 strokes per minute. Be careful not to heat the magnet.

at 1120° C. Alloys such as nickel -iron may lose their magnetism at temperatures ranging from below room temperature as high as 770° C, depending on the ratio of nickel to iron. Place any one of the above metals or alloys near a magnet, at ordinary temperatures, and it will be attracted. Heat it above the Curie temperature and the attraction is lost. As it cools, the magnetic attraction returns. Alternate heating and cooling creates an alternating magnetic force.

How It Works. In operation, a facsimile of Tesla's motor consists of a movable rider made of a soft magnetic material that is pulled in one direction by a spring and in the opposite direction by a magnet -the magnet being the stronger of the two forces. The rider is pulled by the magnet to a position where it can be heated by a flame (or other heat source).

When the rider reaches the Curie temperature, it is no longer attracted by the magnet and is pulled away from the flame by the spring. The rider cools rapidly to below the Curie temperature, re- gains its magnetic properties, is again attracted by the magnet to a position over the flame; and the cycle repeats itself.

The frequency of the rider oscillation depends on the heating and cooling cycle. Once the operation has started, the magnetic rider will remain close to the Curie transformation point and will lose and regain its magnetic properties by variations of only a few degrees above or below that temperature.

A Bunsen burner or hand propane torch will do an excellent job of heating. If these are not available, a candle will serve the purpose. Or, if you want to keep up with the latest trends in science, you can demonstrate the conversion of solar energy by heating the rider with a small magnifying glass.

Construction. The frame of the motor shown (above and on page 114) was made of aluminum since it is easy to work and the non -magnetic qualities of aluminum will not be attracted by the magnetic field. You can build the motor to operate with almost any size of magnet. Small alnico magnets are available in hardware stores. Naturally, a more powerful magnet is easier to use -it will pull from a greater distance, and it also permits the use of a heavier spring. In a model similar to that shown, a 2 -ounce


December, 1966 71



CURBING THE TIDE of entries to

our contest on nonsensical remarks about electronics has the appearance of an impossible task. And why not? Sure- ly you've heard a wild, implausible, or inane remark about electronics. Send it in and you may win a soldering gun -so you'll be able to turn the heat on when the next remark is made in your presence.

Typical remarks have appeared in the July, September, and November issues.

Best of the Lot. Since our last "Se- quel," the comment that got the biggest reception here was one made by a bright -eyed secretary who, when asked ( over the telephone) if a missing carton of capacitors had arrived, replied, "No, but there's a box full of farads."

Talk About TV. About half of the entries received in the past month have been about TV- installation or repair. As might be expected with such a popular topic, there are innumerable dupli- cations.

The most common TV tale is about the housewife who sees all of the dust inside the TV set. Since most wives are un- nerved at the sight of such filth, they set forth and wash out the insides with Soilax -or a similar cleaner -whereupon the husband in question tightens all loose screws and bolts. As far -fetched as this might sound, it apparently has happened from coast to coast -many times over.

Confusion about color TV is a domi- nant topic and we couldn't help laughing at the recommendation not to use 300 - ohm twin lead because it "flattens out

the picture." Or at the story of the housewife who, having moved back into the hills where electric service was not available, asked the technician to "change her TV over to gas."

Now Come the Puns. Possibly because some of the "real life" remarks are too silly to be believed, many readers are submitting puns and other jokes. It's impossible to resist publishing some of them although this was not the original intent of the "No Gun" contest.

The editorial staff particularly liked the letter from a bionic laboratory that asked for a soldering gun because they "wanted to attach a resistor to the stove -they always wanted an ohm on the range." And the one about the electronics technician who had been working late and arrived home to be greeted with, "Oh, Henry, wire you insulate?"

The "classic" pun is so terrible that only engineers will get it; but, as the story goes, a case of butter was missing from a ham club banquet. The problem was solved when one member remarked, "After all, what's Butterworth to Cheby- shev f"

Winners. This month soldering guns went to Thomas Collins, J. Engel, M. J. Ehrenburg, Robert MacElvain, Kevin Garrity, Walter F. Smith, and Donald Strachan.

Send as many entries as you wish to "Gun Contest," POPULAR ELECTRONICS, One Park Avenue, New York, N.Y. 10016. The date of the postmark determines the winner in case of a tie. -




BRIDGE CIRCUIT QUIZ By ROBERT P. BALIN

Most electronic technicians are familiar with the widely used Wheatstone bridge. But many are not so familiar with other types of bridges commonly used in the laboratory for measurement of impedance- resistive, reactive, inductive, or capacitive -at frequencies well up into the UHF band. Bridges employ the so- called null method to measure an unknown quantity, either directly or by computation. In the latter case, values of some of the fixed and adjustable components in the bridge are substituted in an applicable equation, which is then solved for the unknown quantity. See how many circuits (A -J) you can identify by name (1-10).

1 CAREY FOSTER 2 HAY 3 HEAVISIDE 4 KELVIN 5 MAXWELL 6 OWEN 7 RESONANCE 8 SCHERING 9 WHEATSTONE

10 WIEN

(An i rsappearoa page 100)

December, 1966 73



ll,,Ijj%' / \;. .!'.té%::ii/ b.: -- '' - ...WII ., ....

¿-%' , gem .-I!'' ' f1 p1 , 11. ¡:, 50 ap ï i/ ii.:. ;¡a Ì mi:`. 'ii\: %%'i'Ì,; .I/....6\

SOLID STATE By LOU GARNER, Semiconductor Editor

GIFT- GIVING during the holiday season can be a brain -wracking, time- consum-

ing chore, or a relatively pleasant, rewarding experience- depending on your financial status, and on the recipient's interests. For example, if your friends are all electronics hobbyists, the task is bound to be a simple one, since suitable gifts are available in every price range, and the electronics hobbyist who "has everything" is as rare Ls the dodo bird.

The catalogs put out by mail -order houses like Olson Electronics, Radio Shack, Lafay- ette Radio, Allied Radio, and Burstein - Applebee make excellent "wish books" and gift - selection guides. (If you want to "drop a hint" to a parent, relative, or friend, simply put a check mark against the items you'd like, insert necessary page markers, and leave the catalog in a conspicuous place.)

If you are operating with a tight budget, consider giving one of the many books on electronic theory that are offered by semiconductor manufacturers -or a subscription to POPULAR ELECTRONICS.

Also available are books on electronic construction projects by Motorola, Semi - tronics, G. E., Texas Instruments, Interna- tional Rectifier and others, that can be used as guides in choosing more unusual- though perhaps costlier -gifts. Simply select a project and make up a package containing the book and all the components specified in the parts list. Or, you could limit your gift to the "special" components called for -this might include a selection of the required semiconductor devices.

With a fatter pocketbook, your gift might be a Conar, Heath, EICO, Allied Radio (Knight -Kit) or Lafayette test equipment kit . . . or a CB transceiver, hi -fi component, antenna rotator, transistorized d.c. power supply, or an automatic "bug" . . .

depending on the recipient's special interests. If you have an unlimited budget, you can

pull out all the stops and let your imagina- tion be your guide.

Reader's Circuit. A reader with the surprising -but familiar -name of Patrick Hen- ry (2408 Queenstone Dr., San Rafael, Calif. 94903) submitted the four -transistor audio

74

amplifier circuit illustrated in Fig. 1. Pat indicates that he made up the amplifier by combining the best features from a number of commercial circuits and suggests its use be limited to low -to- medium power applications.

At first glance, the circuit seems akin to the four -transistor design featured in the "Update to Solid State" project in the Sep- tember, 1966, issue of POPULAR ELECTRONICS. However, a closer examination reveals a number of important differences. Pat used single -ended class B output amplifiers rather than the push -pull arrangement described in the article, and uses a phase- inverter driver and a different type of biasing network.

An audio signal at JI is applied to the base of Ql, serving as a common -emitter preamplifier, through d.c. blocking capacitor Cl, and GAIN control RI. Resistor R2 supplies the base bias, and R5, bypassed by C2, provides stabilization. Resistor R3 is the collector load.

The amplified output at the collector of Q1 is coupled through C3 to Q2, a split - load phase inverter. Base bias for this stage is furnished through voltage divider R4 -R6, with R7 and R8 acting, respectively, as collector and emitter loads.

The output signal from Q2 is direct - coupled to power amplifiers Q3 and Q4, biased by respective voltage developed across R7 and R8. Emitter resistors R9 and R10 act to stabilize and balance the power amplifier stage. The output signal is applied to the speaker through d.c. blocking capacitor C4. Operating power is furnished by battery Bl , through switch Sl.

Standard parts are used throughout the circuit. Transistors Ql and Q2 are 2N410's, while Q3 and Q4 are 2N456's. Potentiome- ter RI is a 500,000 -ohm audio taper unit and Jl is a standard phono jack. The capacitors are all 15 -WVDC electrolytics, although a higher voltage rating (up to 25 volts) can be used. Except for R9, which is a 1 -watt resistor, and R10, which is a 1.3 -ohm fila- ment choke, all resistors are half -watt types. Switch Si can be combined with RI, or can be a separate slide or toggle type.

The amplifier can be assembled on a met-

POPULAR ELECTRONICS



RI,

500K

IR2 R3 R4 150K IK 200K

2N410

17K5

C3 305F.

+ C2 30pF.

R7 1K

2N456

R6 R8 RIO 27K 1K 1.3.n

SI

BI - 12V -

R9 Ion

+ 1001F.

SPKR

Fig. 1. Reader Patrick Henry came up with this design for a four-transistor amplifier by combining good features from selected commercial circuits. Output is in the medium power range.

al chassis or on a phenolic board, as preferred. One advantage of using a metal chassis is that it can also serve as a heat sink for Q3 and Q4, which must be heat - sinked. The completed amplifier can be used with any standard PM speaker having a 3.2- to 16 -ohm voice coil. In general, the higher the speaker impedance, the better the system's low frequency response; and remember that larger speakers (6 -to 8 -inch) are more efficient than the miniature types. Battery BI can be a 12 -volt lantern type, or it can be made up of eight flashlight cells in series.

Manufacturer's Circuit. Many electronic equipment circuits, including stabilized oscillators, signal generators, transistorized test meters, characteristic curve tracers, and calibrated amplifiers, call for regulated d.c. power supplies. The simple voltage- regula- tor circuit shown in Fig. 2 is one of several power transistor circuits discussed in a recently published bulletin by Bendix's Semi- conductor Division (Holmdel, N.J.).

This circuit is capable of maintaining a constant output voltage even with relatively wide variations of input voltage or load conditions. Due to its utter simplicity, it can be added to an existing power supply, or can serve as an integral part of a regulated power supply design.

Employing the principles of conventional series regulation, the circuit utilizes the internal collector- emitter resistance of Ql, which varies with changes in the applied voltage or in circuit loading, to provide automatic voltage regulation. The regulation is controlled essentially by a stabilized base bias that is furnished and maintained by resistor RI and zener diode DI.

December, 1966

Component values will, of course, vary with design requirements, but with a nominal 12 -volt d.c. source, Bendix suggests a B -5000 npn power transistor for Q1 and a 1N2044 -3 zener diode for Dl. Resistor R1 is a 22 -ohm, 5- or 10 -watt unit. With these values, the circuit maintains a steady out-

10-14 VDC

8-5000

Fig. 2. Voltage regulator by Bendix maintains a relatively constant output, notwithstanding wide variations of input voltage or load conditions.

put of 8.6 ± 0.25 volt across a 180 -ohm load, with a d.c. input of from 10 to 14 volts. In fact, the output will drop less than 1 volt even if the load is reduced to only 4 ohms.

The regulator circuit can be assembled in a small metal box for test purposes or on a suitable phenolic board or etched circuit board for addition to an existing power supply. An adequate heat sink should be provided for Ql.

New Developments. A solidstate, positive - temperature -coefficient thermistor in a new hermetically sealed, hard -glass package is now being produced by Texas Instruments, Inc. (13500 N. Central Expressway, Dallas, Texas). The new unit (Fig. 3) is only one-

75



third the volume of the earlier molded type shown. Dubbed a Sensitor, and identified as type TG1 /8, the 1/2-watt silicon unit is ideal for temperature- sensing applications and for temperature compensation in transistor bias control ànd amplifier circuits. The TG1 /8 features a linear resistance curve with temperatures between -55° and + 125° C, and is available in 32 ohmic values, ranging from 10 to 2700 ohms.

If you like to work with UHF circuitry - whether as a ham or an an advanced student- you'll be interested in a new npn silicon planar epitaxial transistor recently announced by the Amperex Electronic Corp. (Slatersville, R.I. 02876). Designated as Type A485, the transistor has a gain -band- width product (fr) of 1500 MHz and can

EARLY MOLDED

TYPE

NEW HARD -GLASS

PACKAGE

Fig. 3. The new positive- temperature- coefficient thermistor by Texas Instruments is only one -third the size of the earlier molded type, as shown here.

provide gain up to 200. Its noise figure is a low 3.5 dB at 200 MHz and only 4.5 dB at 450 MHz. A low -power device, the A485 is suitable for use in receivers, r.f. amplifiers, signal generators, test circuits, telemetry equipment, and other projects requiring high gain and low noise.

Transitips. How do you select your transistor audio transformers? By price? By size? By impedance ratios? By power rating? By brand name?

In practice, any one of these criteria, taken alone, can lead to disappointing results; for there is no such "animal" as a "perfect" transformer. At best, any standard commercial transformer design represents a compromise between such factors as cost, overall size, weight, frequency response, efficiency, and power -handling capability.

For example, take the output stage illustrated in Fig. 4. Although a push -pull amplifier, it can be considered as a single - ended stage if the lower half of the circuit (Q2) is blocked out. In this circuit, output transformer Ti must: (1) provide a d.c. path for Ql's collector current; (2) act as a collector load for the transistor; (3) match

76

the stage's output impedance to the loudspeaker's voice coil; and (4) transfer power efficiently from the primary to secondary windings.

Equally important, the transformer must not: (1) introduce excessive power losses; (2) discriminate against specific frequencies

TO DRIVER

Fig. 4. A transistor audio transformer represents a compromise between ideal circuit requirements and factors of physical size, weight, and cost.

within its operating range; (3) introduce unwanted signals, such as spikes; (4) dis- tort or otherwise change waveform of re- produced signals; (5) discriminate against signals of different amplitudes, such as transferring a high -level signal more efficiently than a low -level signal; and (6) produce a strong magnetic field that can couple to nearby components.

A good -quality audio output transformer is one which: (1) has the required impedance ratio, (2) has comparatively low d.c. resistance, and (3) can tolerate relatively large direct current levels. Unfortunately, these desirable characteristics can be obtained only at the expense of increased cost, size and weight.

To obtain a low d.c. resistance, the manufacturer must use a large size wire in the windings. This calls for more copper (which is expensive), and requires more space. Similarly, for maximum efficiency and good low- frequency response, the transformer must exhibit resistance to saturation by large signals. This means that the manufacturer has to use more iron in the transformer's core, and here again this calls for an increase in the size, weight, and cost of the transformer.

Inasmuch as wire and core size both affect a transformer's overall size, a good rule of thumb to follow -space permitting -is: the larger the transformer, the better.

Until next year -Happy Holidays! -Lou

POPULAR ELECTRONICS



-- --- -- - - - - - - - --- - -- AMATEUR RADIO By HERB S. BRIER, W9EGQ Amateur Rodio Editor

GETTING THE MOST FROM YOUR DIPOLE OR BEAM ANTENNA

IT IS a well -known fact that a horizontal, center -fed, half -wave dipole, with or

without traps, radiates best in a fairly wide pattern broadside to its length and poorest off its ends. But comparatively few people know the actual difference in signal strength or actual difference in how well they get out in various directions because of the orientation and directional characteristics of their antennas.

Here are some figures. Under normal conditions, the difference between broadside and end -fire signal reports when you're using a half -wave dipole averages less than half an "S" unit on the 3.5 -MHz band and about one "S" unit on 7 MHz. On 14 MHz, the difference goes up to two to three "S" units ; and on 21 MHz and higher, it averages about three "S" units.

From a practical standpoint, it is unim- portant in what direction you string a horizontal, 1/2-wave, 3.5- or 7 -MHz dipole; but for working all states from most areas of the U.S. on the higher frequencies, string- ing a 1/2-wave dipole north and south is probably the best compromise. On the 14 -, 21 -, and 28 -MHz bands, however, where directivity is more pronounced, a 1/2-wave dipole is 33', 22', and 161/2' long, respectively; and many locations can accommodate two such antennas mounted at right angles to each other. By switching from one to the other, a rotating beam antenna effect can usually be obtained -especially on DX.

On the other hand, a small rotary beam requires less room than the two dipoles and provides power gain as well as directivity.

December, 1966

AMATEUR STATION OF THE MONTH

Just count those TV screens! Bob Dreste, K7VOR, Phoenix, Arizona, operates on 440 -MHz amateur TV with a Blonder- Tongue vidicon camera chain, iconoscope slide camera, and a home -brew transmitter feeding a 10- element beam antenna atop a 65' tower. Bob also works 50 MHz (22 states confirmed), is an ARRL Assistant Di- rector, and an Official Bulletin Station; the 50 -MHz antenna is a 6- element beam. K7VOR will receive a one -year subscription to POPULAR ELECTRONICS for submitting this winner for December in our Amateur Station of the Month contest. If you would like to enter the contest, send us a clear picture of your station with you at the controls and some information about your radio career and the equipment you use. Even if you don't win, your photo may be used if space permits. Entries should go to: Amateur Radio Contest, c/o Herb S. Brier, P.O. Box 678, Gary, Indiana 46401.

77



Larry Trummel, WA90MD, Lane, Ill., uses a dipole antenna, and George W. Moran, W2DGZ, Woodhaven, N. Y., (right) finds a simple vertical antenna satisfactory for 40 -, 20 -, 15 -, and 10 -meter operation. George's antenna gets nourishment from a Drake T -4X transmitter feeding a Heathkit HA -14 linear amplifier, which, in turn, feeds a Drake R -4A receiver. Larry transmits on a Johnson "Viking -Il," with a VFO, and receives on a

Hallicrafters SX -111. Their records: Larry worked 49 states in five months as a Novice, and as a General has added many foreign contacts; George counts WAC, WAS, and RCC among his various certificates.

But a beam is not much good unless it is aimed properly. While you don't have to aim it within half a degree, an error of more than ten degrees is too much.

The first step in aiming a beam accurately is locating true north from your location. Sighting the North Star will locate it within a degree. Also, a magnetic compass will locate magnetic north, and if you add the proper amount of variation for your area, you can readily determine true north.

Next, you need a world DX map drawn on a polar projection which identifies countries both by name and by call -letter pre- fix. When you hear a station called or mentioned, a glance at the map will identify the country and indicate where to aim your beam. But be sure to get a polar map; directions and distances indicated on a

common Mercator map can be most confusing. For instance, Japan appears to be east of the United States on a Mercator world map. By the Great Circle route -the way radio signals usually travel -Japan is actually northwest of the United States. Similarly, Australia appears to be southeast of the U.S. on a Mercator map; actually, it is west.

There may be times when the shortest route between two stations is not the best way to beam your antenna. Propagation conditions could be such as to make it more desirable to rotate your beam 180° and shoot your contact the long way around. You won't notice any difference with a bi- directional dipole, but a beam with a good front -to -back ratio will give you some am- munition for ragchewing when you go west instead of east.

78

The American Radio Relay League's "Amateur Radio Map of the World" and the Call Book's "Great Circle Chart of the World," available from amateur supply houses, are both excellent DX maps. In addition, hanging these maps on the wall really dresses up a ham shack.

Code Practice. Whether you have just memorized the code and your aim is 5 wpm for a Novice or Technician license, or you are aiming for 13 wpm to upgrade your license to General, or even 20 wpm for Extra Class, the only way you can improve your copying ability is by regular practice. Sta- tion W1AW, the headquarters station of the American Radio Relay League, Inc., makes the practice easy to get if you have a shortwave receiver.

For those who are not familiar with W1AW's schedule, code practice material is sent twice a day simultaneously on 1.805, 3.555, 7.08, 14.1, 21.075, 50.7, and 145.6 MHz at the following times and speeds. Early session: daily at 0300 GMT (7:30 p.m., EST; 6:30 p.m., CST; 5:30 p.m., MST; 4:30 p.m., PST) at speeds of 10, 13, and 15 wpm. Evening session: daily at 0230 GMT (9:30 p.m., EST; 8:30 p.m., CST; 7:30 p.m., MST; and 6:30 p.m., PST). Speeds on Sunday, Tuesday, Thursday, and Saturday evenings are 5, 7%, 10, and 13 wpm; on Monday, Wednesday, and Friday, they are 15, 20, 25, 30, and 35 wpm.

Approximately 10 minutes of code is sent at each speed. The start of each session is announced by "QST QST QST DE W1AW W1AW W1AW," repeated over and over.


POPULAR ELECTRONICS



ON THE CITIZENS BAND By MATT P. SPINELLO, C2060, CB Editor

THE AUTOMOBILE Manufacturers As- sociation and the General Motors Re-

search Laboratories have announced operating test programs of the Highway Emergency Locating Plan (HELP). In the initial test, the City of Detroit Department of Streets

and Traffic and the GM Research Labs have inaugurated an experimental CB radio emergency service along the John C. Lodge expressway from Cobo Hall to

Eight Mile Road. The system is designed to improve the flow of traffic along a main city traffic artery through use of CB radio by private motorists.

Under the experimental program, the De- partment of Streets and Traffic maintains a base station in the Herman Kiefer Hospital headquarters of the National Proving Ground for Freeway Surveillance. The GM Research Laboratories has supplied 100 CB transceivers for the system hookup. Some have been installed in City of Detroit vehicles, others in cars of selected GM em- ployees who commute daily on the expressway. Operators of both City and GM CB- equipped vehicles have been instructed to call the base station only for expressway emergencies. The base station then directs

CB HELP PLAN

TESTED

In HELP test program set up by the City of Detroit and GM Re- search Labs, operators of mobile CB transceivers call base station (at right) when an emergency occurs along the John Lodge expressway, and the base station directs the police expressway patrol to the scene.

December, 1966

the police expressway patrol to the scene of the emergency.

Michigan's highway department has installed special markers along the freeway route from downtown Detroit to Lansing as well as signs advising that the highway is being monitored by CB radio. Special dis- play banners also have been posted at each of the monitoring centers where HELP literature is being handed out to interested parties.

The purpose of the test programs is to gather data in support of the AMA petition to the FCC requesting that two new CB channels be reserved for highway emergency use. The FCC had indicated earlier that more information was necessary to determine whether such exclusive channels were needed.

A somewhat similar experimental CB system is now operating in the Kokomo, Ind., area where GM's Delco Radio Division has a CB base station in its plant. Calls for help received at the station are relayed to the city police or county sheriff';; department. The calls received at Delco so far have con- cerned automobile accidents and motorists stalled for lack of gas. Researchers indicate, however, that the Kokomo system has proved that first aid for injured motorists can be expedited by HELP.


79



ENGLISH -LANGUAGE BROADCASTS TO NORTH AMERICA FOR THE MONTH OF DECEMBER

Prepared by ROBERT LEGGE

COUNTRY

TO EASTERN AND CENTRAL NORTH AMERICA

CITY TIME -EST TIME -GMT FREQUENCIES (MHz)

AUSTRALIA Melbourne 7:15-8:15 a.m. 1215-1315 11.71 CANADA Montreal 7:15-8:15 a.m. 1215-1315 5.97, 15.32 DENMARK Copenhagen 7:30-8 a.m. 1230-1300 15.165 FINLAND Helsinki 7:15-7:45 a.m. 1215-1245 15.185 (Tues., Sat.) GREAT BRITAIN London 10:30 a.m.-12:30 p.m. 1530-1730 15.26,17.81 SWEDEN Stockholm 9-9:30 a.m. 1400-1430 17.84

EVENING BROADCASTS

ALBANIA Tirana 7-7:30 p.m. 0000 -0030 7.265 BULGARIA Sofia 7-8 p.m. 0000 -0100 6.07 CHINA Peking 8-10 p.m. 0100 -0300 11.945, 15.06 CUBA Havana 8-11 p.m. 0100 -0400 6.17, 11.76 CZECHOSLOVAKIA Prague 8-9 p.m. 0100 -0200 5.93, 7.115, 7.345 ECUADOR Quito (HCJB) 9-11:30 p.m. 0200 -0430 9.745, 11.915 EGYPT Cairo 8:30-10 p.m. 0130 -0300 9.475 GERMANY Berlin 8-9 p.m. 0100 -0200 6.16, 9.73

Cologne 8:30-9:50 p.m. 0130 -0250 6.075, 9.64 GREAT BRITAIN London 4:15.10:30 p.m. 2115 -0330 6.195, 7.13, 9.51 HUNGARY Budapest 8:30-9:30 p.m. 0130.0230 6.235, 9.833 ITALY Rome 8-8:20 p.m. 0100 -0120 6.01, 9.63 JAPAN Tokyo 6:45-7:45 p.m. 2345 -0045 11.78, 15.135 LEBANON Beirut 9:30-10 p.m. 0230 -0300 9.71 NETHERLANDS Hilversum 8:30.9:30 p.m. 0130 -0230 9.59 (Bonaire relay) PORTUGAL Lisbon 9-9:45 p.m. 0200 -0245 6.025, 6.185 ROMANIA Bucharest 8:30.9:30 p.m. 0130 -0230 6.15, 9.57 SOUTH AFRICA Johannesburg 7:30.8:30 p.m. 0030.0130 9.525, 11.90 SPAIN Madrid 8-9:30 p.m. 0100 -0230 6.13, 9.76 SWEDEN Stockholm 8:15-9:45 p.m. 0115.0245 5.99 SWITZERLAND Berne 8:15-9-15 p.m. 0115 -0215 5.965, 6.12, 9.535 U.S.S.R. Kiev 7:30-8 p.m. 0030 -0100 7.12, 7.31, 9.665

(Mon., Thurs., Fri.) (Tues., Fri., Sat.) Moscow 5-5:30 p.m. 2200 -2230 7.15, 7.31, 9.665

& hourly to & hourly to 12-1 a.m. 0500 -0600

VATICAN Vatican 7:50-8:10 p.m. 0050 -0110 5.985, 7.25, 9.645

TO WESTERN NORTH AMERICA

COUNTRY CITY TIME -PST TIME -GMT FREQUENCIES (MHz)

ARGENTINA Buenos Aires 10-11 p.m. 0600 -0700 9.69 (Mon.-Fri.) (Tues. -Sat.)

AUSTRALIA Melbourne 5-7 p.m. 0100 -0300 15.22, 17.84 BULGARIA Sofia 8-8:30 p.m. 0400 -0430 6.07 CHINA Peking 7-9 p.m. 0300 -0500 9.457,11.82,15.095

Taipei 6:50-7:50 p.m. 0250 -0350 11.86, 15.345 CUBA Havana 10:30-12 p.m. 0630 -0800 6.10 CZECHOSLOVAKIA Prague 7:30-8:30 p.m. 0330 -0430 5.93, 7.115, 7.345 GERMANY Berlin 7:45-8:15 p.m. 0345 -0415 5.96, 9.65

Cologne 9-9:40 p.m. 0500 -0540 6.145, 9.735 HUNGARY Buda pest 7-8 p.m. 0300 -0400 6.235, 9.833 JAPAN Tokyo 6-7 p.m. 0200 -0300 15.135, 17.825 KOREA Seoul 7-7:30 p.m. 0300 -0330 11.925 PORTUGAL Lisbon 8-8:45 p.m. 0400 -0445 6.025, 6.185 SOUTH AFRICA Johannesburg 6:30-7:30 p.m. 0230 -0330 9.525,11.90 SWEDEN Stockholm 7:15-7:45 p.m. 0315 -0345 5.99 SWITZERLAND Berne 8:15-9-15 p.m. 0415 -0515 5.965 U.S.S.R. Moscow 7-10:30 p.m. 0300 -0630 9.54, 9.735, 11.755




SHORT -WAVE LISTENING By HANK BENNETT, W2PNA /WPE2FT Short -Wave Editor

BROADCASTING STATION NEWS AROUND THE WORLD

THE Australian Administration Territorial Government recently opened its sixth

new broadcasting station. This regional station is located at Mount Hagen, Papua, and the call -sign is VL8CH. The schedule calls for transmissions in English and native languages at 0700 -1100. Station VL8CH should prove to be a difficult catch for North American DX'ers, since the frequency being used is 2450 kHz, and the power rating is only 250 watts.

According to Radio New York Worldwide, a new radio station (reportedly backed by American money) is already on the air in South Korea. Its announced purpose is to transmit the truth to millions of listeners in Communist sections of Asia. The station is called Radio Free Asia and is run by the Korean Cultural and Freedom Foundation. This is a private, non -profit organization with headquarters in Washington, D.C. At present, Radio Free Asia is using the facilities of a 500,000 -watt station run by the South Korean government; however, the construction of a transmitter is planned.

The Voice of the Himalayas, Katmandu, Nepal, will begin testing soon, if it has not already done so, with two 100,000 -watt transmitters, probably on or near 7105 kHz.

When the tiny British possession in the South Atlantic, Tristan da Cunha, celebrated its 150th anniversary, a new radio station was inaugurated to mark the occasion. Details are lacking, but in view of the fact that the population of Tristan da Cunha amounts to only several hundred people, the station is more likely to be a utility station than a regular broadcaster.

Word has been received that the Armed Forces Caribbean Network broadcasts on 1200 kHz from its main studio in El Morro at Fort Brooks, Puerto Rico. All programming is rebroadcast from satellite stations at Roosevelt Roads Navy Base and Fort Allen, Ponce, as well as from an affiliated station at Ramey Air Force Base. The latter operates on 870 kHz with 50 watts, according to Major C. F. De Smet, Information Officer.

DX'ers all over the world are receiving surprises nowadays in the form of verifica- Vn-1 cr-ds '^or- r . dio Aparecida, Brazil. Some of these QSL's are in confirmation of

December, 1966

reports sent in more than 15 years ago! Re- sponsible for the change is a 23- year -old student, Jose Dinys, who is now acting as International Correspondence Chief for the station. He says that all reports will be verified and that one or two IRC's will be appreciated from those who would like to have airmail replies. Mr. Dinys is also interested in exchanging stamps with other collectors. Reports should be sent to: Praca N. S., Aparecida 315, Aparecida, Sao Paulo,


In San Angelo, Texas, Explorer Post 382 of the Boy Scouts of America took part in a field day exercise. Scout Robert Montgomery is shown at the controls of a Hammarlund HQ -120 receiver (above) with advisor Roy Baker in the background. Below, Scout Joe Milam takes his turn at a Hallicrafters SX -110. All participating Explorers helped with the various chores, from digging of post holes for antenna towers to laying of wire for electrical power.

81



FOREIGN -LANGUAGE BROADCASTS TO NORTH AMERICA

Prepared by BILL LEGGE

LANGUAGE STATION TIME -EST TIME -GMT FREQUENCIES (MHz)

ARABIC Cairo, Egypt 6:30 -7:30 p.m. 2330 -0030 9.475

Damascus, Syria 8 -9 p.m. 0100 -0200 9.605

BULGARIAN Sofia, Bulgaria 8 -8:30 p.m. 0100 -0130 6.07

CHINESE Peking, China 8 -10 p.m. 0100 -0300 9.92, 12.01, 15.095

10 -12 p.m. 0300 -0500 9.48, 12.01, 15.08

CZECH /SLOVAK Prague, Czechoslovakia 8:30 -9 a.m. (Sun.) 1330 -1400 15.285, 17.825

10 -10:30 p.m. 0300 -0330 7.345, 5.93, 7.115

DANISH Copenhagen, Denmark 7 -7:30 a.m. 1200 -1230 15.165

8 -9 p.m. 0100 -0200 9.52

DUTCH Brussels, Belgium 6:15 -8 p.m. 2315 -0100 9.615

Hilversum, Holland 9:30 -10:50 p.m. 0230 -0350 9.59

FINNISH Helsinki, Finland 7:15 -10:10 a.m. 1215 -1510 15.185

FRENCH Brussels, Belgium 6:15 -8 p.m. 2315 -0100 9.615

Lisbon, Portugal 9:15 -10 p.m. 0215 -0300 5.985

Paris, France 4 -5 p.m. 2100 -2200 11.885, 15.13

Rome, Italy 8:20 -8:35 p.m. 0120 -0135 6.01, 9.63

Vatican City 8:10 -8:35 p.m. 0110 -0135 5.985, 7.25, 9.645

GERMAN Berlin, Germany 8:30 -9:30 p.m. 0130 -0230 5.96, 9.73

Cologne, Germany 7 -10 p.m. 0000 -0300 6.10, 9.545

10 p.m. -1 a.m. 0300 -0600 6.10, 9.64

Vienna, Austria 7 -9 p.m. 0000 -0200 9.77

HUNGARIAN Budapest, Hungary 7 -7:30 p.m. 0000 -0030 6.235, 9.833

9 -10:30 p.m. 0200 -0330 6.235, 9.833

ITALIAN Rome, Italy 5:30 -8 p.m. 2230 -0100 6.01, 9.63

JAPANESE Tokyo, Japan 7:15 -7:30 a.m. 1215 -1230 9.505, 9.605

8:30 -9 p.m. 0130 -0200 15.135, 17.825

NORWEGIAN Oslo, Norway 10 -11:30 a.m. 1500 -1630 15.175

4 -5:30 p.m. 2100 -2230 9.61

PORTUGUESE Lisbon, Portugal 7 -9 p.m. 0000 -0200 6.025, 6.185

9:45 -11 p.m. 0245 -0400 6.025, 6.185

RUMANIAN Bucharest, Rumania 6:15 -7 p.m. 2315 -2400 6.15, 9.57

10:30 -11 p.m. 0330 -0400 6.15, 9.57

RUSSIAN Moscow, U.S.S.R. 7 a.m. -12:30 p.m. 1200 -1730 15.15

6:30 -7 p.m. 2330 -0000 7.15, 7.31

8:30 -9 p.m. 0130 -0200 7.15, 7.31

SPANISH Buenos Aires, Argentina 8 -9 p.m. 0100 -0200 9.69

11 -12 p.m. 0400 -0500 9.69

Havana, Cuba 6 a.m. -4 p.m. 1100 -2100 6.135, 15.30

5 -11 p.m. 2200 -0400 6.135, 9.55

Quito, Ecuador 6 -9 a.m. 1100 -1400 9.745,11.915,15.115

7:30 -9 p.m. 0030 -0200 6.05, 9.745, 11.915

SWEDISH Stockholm, Sweden 8 -8:45 p.m. 0100 -0145 5.99

9:30 -10:15 p.m. 0230 -0315 5.99

UKRAINIAN Kiev, U.S.S.R. 7:30 -8 p.m. 0030 -0100 7.11, 7.31




IIVGa "has 'em both"

MODEL 65 -2 $3995 Est

BOOSTER COUPLERS IN 300 OR 75 OHM

For Deluxe Home & Commercial Use Finco's famous 2 -tube, 4 -set VHF -TV OR FM Distribution Amplifier is now available for 75 OHM CO -AX or 300 OHM operation. Price? You can't beat it! Rugged quality? Finco's got it! Performance? Finco challenges 'em all! Equip either model with Finco low -loss splitters ( #3001 or #30031 and you can drive up to 16 sets in a master antenna system!

FINCO MODEL #65-1 529.95 list Outstanding Features:

350.000 microvolts maximum input with - 848 to each output Maximum signal output of .85 volts in

each of 4 outputs Low noise 61-IA5 premium tubes One 300 ohm input - 4 300 ohm outputs Silicone

diode rectifier for dependability Flat response - S db per 6 me channel Ventilated perforated

steel cabinet 67,,, x 3%,,, o 37,76' Metal enclosed to eliminate shock hazard - easy access for servicing

Easy mounting and connecting All fittings & brackets supplied 01 listed AC cord -117 volts, 60 cycles 100% test for all electrical characteristics

FINCO MODEL #65-2 $39.95 list Outstanding Features:

400,000 microvolts maximum input with -I 6dB to each output 200,000 microvolt input - 1 volt output per band Low noise 6HÁ5 premium tubes One 75 ohm input - 4 75 ohm outputs Most compatible "F" type input and output fixtures Ultra -flat frequency response and complete HF isolation Venti fated perforated steel cabinet 6'., x 3',, x 3 °,,," Metal enclosed to eliminate shock hazard - easy access for servicing Easy mounting and connecting

All fittings & brackets supplied UL listed AC cord -117 volts, 60 cycles 100% test for all electrical characteristics

`Q Of THE WORLD ¡q

coron 1°i ALL FINCO PRODUCTS ARE ENGINEERED FOR COLOR, F /NCO THE FINNEY COMPANY 34 West Interstate Street, Bedford, Ohio 44014

qN0 FM ANTI.N

December, 1966 CIRCLE NO. 15 ON READER SERVICE PAGE 8 3



Courier's 23- channel solid -state CB rig. Guaranteed for 10 years!

Look for everything you've ever wanted in a CB rig in Courier's TR -23S. Silicon -transistors throughout bring the size down to 53/4" W x 61iá" D x 17 /s" H. Crystals supplied for all 23

channels. Complete with microphone. Illumi- nated S meter. Illuminated channel selector. PA system. Auxiliary speaker jack. Single - knob tuning. Modulation indicator. DC cord. Exclusive Courier "Safety- Circuit" to protect against mismatched antenna, incorrect polarity, and overload. Pius the biggest guarantee in the business -10 full years!

, V I COURIER COMMUNICATIONS, INC.

A suf,d ,,ry of

. electronics communications inc. 56 Hamilton Avenue, White Plains, N.Y.

Yes! I'd like to know all about the $169 Courier TR -23S with the 10 -year guarantee.

Name

Address

City County State PE 612

CIRCLE NO. le ON READER SERVICE PAGE

ELAPSED

TIME

INDICATOR KEEPS

TRACK OF

STYLUS WEAR

HOW do you know when it's time to change your hi -fi cartridge stylus,

or demagnetize your tape recorder head, or overhaul the engine on your boat ? By logging operating time in a book? Now there's a better way. A new 13/4" x :%" direct -reading elapsed time meter developed by Curtis In- struments, Inc., Mt. Kisco, New York, can log up to 5000 hours of operating time before recycling.

The timer consists of a glass tube with two columns of mercury separated by an electrolyte gap. When a small direct current is passed through the tube, mercury is transferred through the gap from anode to cathode, the displacement being a linear measure of the hours of operation.

For a.c. operation, the timer is combined with a small epoxy- encap- sulated transformer and rectifier, and the device to be timed is plugged into the assembly. Prices start at $8. Data sheets and distributor list are available free from the manufacturer.

CIRCLE NO. 25 ON READER SERVICE PAGE-*



ASSIST (Continued from page 38)

Detrola auto radio, circa 1932; has 5 tubes. Schematic needed. (Leroy Gross. 150 W. Alachua, Cocoa Beach, Fla. 32931) Gilfillan Bros. Model 56A receiver, circa 1946; tunes BC; has 5 tubes. Schematic and specifications needed. (Bill Denton, Rt. 1, Box 612B, Arroyo Grande, Calif. 93420) Silvertone Model 101.772 -1 wire recorder; has 6 tubes. Spring for cam lever assembly and stainless steel recording wire needed. (Jim Holland, 2641 Elmdale Ct., Palo Alto, Calif.) RM E/ Electro -Voice Model 4350 receiver. Instruction manual or schematic needed. (John E. Spiegel, 1586 Moravia Ave., Holly Hill, Fla. 32017;

Stromberg- Carlson Model 1121 -PL receiver; tunes BC, FM and s.w.; has 11 tubes. Schematic and source of power transformer needed. (Steve Ordinetz, RFD #2, Chester Depot, Vt. 05144 )

ID -6 A /APN -4 oscilloscope" surplus. Schematic, operating manual, and power supply data needed. ( William Weir, 406 Prospect St., Berea, Ky. 40403)

Supreme Model 599A tube checker. Schematic needed. ( Lou E. Smith, 2405 5 St., Meridian, Miss.) Hammarlund "Super -Pro" receiver, type RHV -2; tunes 1300 kHz to 40 MHz. Schematic and alignment data needed. (M.J. Vandermolen, Rt. 2, Box 33, Perkins, Okla. 74059) Zenith Model 26 -201 receiver, ser. S357088, circa 1940; tunes 550 kHz to 24 MHz on 3 bands; has 6 tubes and magic eye. Schematic needed. (D.H. Lord, 411 Red Chimney Dr., Warwick, R.I. 02886)

McMurdo Silver Model 904 capacitance resistance bridge, Model 900 volt ohm Vomax, Model 905 signal tracer gain test set. Schematics and operating manuals needed. (Melvin V. Berninger, 16 Grand St., Reading, Mass. 01867) Hickok Model 202B volt -ohm- milliammeter, Series B. Schematic needed. (George M. Kistler. 2956 Loyola St., Sacramento, Calif. 95826)

Philco Model 39 -116 receiver, code 121, circa 1939; has 13 tubes. Schematic, dial face plate, and source for parts needed. (George A. Bingaman, Box 685, Glenròck, Wyo. 82637) Philco Model 42 -350 receiver; circa 1930; tunes AM and FM on 3 bands; has 6 tubes. Schematic needed. (Gary Schneider, 4413 Carnation, Cincinnati, Ohio 45238)

Meissner Model 9 -1065 phono -recorder p.a. system. Operating and instruction manual needed. (Barry Weis- man, 112 Ridge Ave., Newton. Mass. 02159)

Motorola Mortel T41G -1A, T51G transceiver, circa 1954; tunes FM from 30 to 54 MHz. Operating manual and TK206 adapter chassis needed. (Robert W. Merdler, 196 S. Jefferson, Saginaw, Mich. 48601) Stewart- Warner Model 206BBS receiver. Schematic needed. (William M. Wilmoth, 230 N. Eufaula Ave., Eufaula, Ala. 36027) Hickok Model RFO -5 oscillograph, circa 1950. Sche- matic and operating manual needed. (Barry Lowry, 1102 Holgutni St., Lancaster, Calif. 93534) Surplus mine detector Model SCR- 625 -C- 2915 -Phila -45- 08. BC- 1141 -E amplifier, made by Horni Signal Mfg. Corp. Operating manuals needed. (William W. Rigden, 103 Madison St., Milton, Fla. 32570)

Philco Model 39 -25 receiver, code 121; tunes BC and 3 to 18 MHz. Schematic needed. (John Boxhorn, 13650 Tremont St., Brookfield, Wis. 53005)

Elgin Model D receiver; tunes BC and 5.5 to 20 MHz; has 7 tubes. Schematic, service data, and K- 38 -B -2 tube needed. (Mike Wheeler, 3523 Altamont Dr., Klamath Falls, Ore. 97601)

Atwater -Kent Model 20 receiver, ser. 226289; tunes BC; has 5 tubes. Schematic and source for parts needed. (SSgt. Orville Gallimore, AF 55287149, 2140th Comm. Sgdn., AFCS, Box 2162, APO, New York 09223)

Hickok Model 450 VOM. Schematic and operating manual needed. (Brad Woelke, 11422 Marion, Detroit, Mich. 48239)

T 193B /VRC -2 transmitter, made by Utility Electronics Corp. for Signal Corps, order #20591- PH -49. Schematic or booklet #TM -11 -607 needed. (Eric Smitt, 609 Oak - field La., Philadelphia, Pa. 19115)

December, 1966

TWO NEW

"plastic view" screwdriver Nils

EASY TO USE, CARRY & STORE

These neat, extremely compact kits fit hip pocket, tool box,

boat kit, glove compartment ... can also be hung on a

wall. Durable "Plastic View" zipper case permits instant

identification of tools. Amber plastic (UL) Service Master handles are shock-

proof, breakproof, have patented spring holding device

that accepts all Xcelite Series 99 blades - lets you add

tools as needed at minimum cost.

Space saving, single -ended interchangeable blades .. .

can be used with Xcelite extensions for extra reach.

99PV -6

Handle and 3 slotted screwdriver blades (3h ". / ", 3íe" tips) 2 Phillips (#1, #2)

99PV -4

Handle and 3 slotted screwdriver blades tips)

r-- O

XCELITE INC. 20 BANK ST., ORCHARD PARK, N. Y. 14127

Send Catalog 166 with information on "Plastic View" Screwdriver Kits.

name

address

city state & zone




SC TT

SCOTT'S NEW ONE- AFTERNOON

TUNER KIT DELIVERS AMAZING FET PERFORMANCE

Now you can get factory -wired performance from a kit that takes only one afternoon to build! Scott's new LT-112B is the only kit with Field Effect Transistor circuitry`, enabling you to enjoy more stations more clearly. Interstation Muting Control effects complete quiet between FM stations ... oscilloscope output allows laboratory -precise correction for multipath distortion.

"Scott's LT- 112... is one of the finest FM stereo tuners we have tested and it is easily the best kit -built tuner we have checked ... Because of its simple construction and trouble -free nature, it is a logical choice for anyone who wants the finest in FM reception at a most remarkable price." HiFi /Stereo Review. LT-112B specifications: Usable sensitivity, 1.8 µV; Cross modulation, 90 dB; Stereo separation, 40 dB; Capture ratio, 2.5 dB; Price, $189.95. 'Patents pending

For complete information on the Scott LT -1126, send for your free copy of Scott's 16 -page full -color illustrated Guide to Custom Stereo.

Scott ... where innovation is a tradition

0 SCOTT" Prices slightly higher west of Rockies. Subject to change without notice.


LETTERS ( Continued from page 12 )

when the dipole was rotated. The sound was equally intense when observed from shore or from a boat in the middle of the lake (Lake Eau Claire, S.E. Eau Claire County, Wis.)

On two occasions, both after sunset, distinct "ping" sounds could be heard in addition to the crackle. On one other occasion, a sunny afternoon, a few whistles were heard. On that same afternoon, I also heard something which I can best describe as a rather low - pitched cricket -type sound. All sounds ceased as soon as the antenna was removed from the water. Passing I r'tor boats did not create any detectable signal.

GEORGE R. ROSSMAN Eau Claire, Wis.

I am an experimenter who is always looking for something unusual to build. I had all the equipment for the Hydronics receiver, so I built it. It works fine in large bodies of water but when I put it in my aquarium the only thing I get is the local radio station (KXKW).

DAVID You NGBLOOD

Lafayette, La.

David, that's one ]Day to listen to your local radio station. George, did you try putting these sounds on a tape recorder and then listening to the recording at a slower speed? D.A., your unit seems to be working fine; apparently, what you need is a large body of water. Elliot, glad you lost your skepticism, but we still don't know if Pìas- monies is for the birds. For what it's worth, Minto is still working away at this project in an effort to find a method of long -range "radio" communication under water.

OUT OF TUNE Powerhouse 2 -Tube Short -Wave Receiver (Au- gust, 1966, page 62). In Fig. 4, L.3 and L, should he transposed; also transpose L3 and L!, in the Parts List.

Static -Free Thermistorized Aquarium Heater (September, 1966, page 74). Resistor Rif should be 10,000 ohms and R7 should he 56.000 ohms.

Four On The Floor (November, 1966, page 75). Dimensions on the drawing are correct but in the Bill of Materials the wood for the exterior sides should be listed as 13ír," x 34" x :,y "; for the exterior top as 131/2" x 19" x ' "; and for the exterior bottom as 127/s" x 171/2" x .'1". .

Update to Solid State (September, 1966, page 44). Caption under bottom photo should read small "metal" clamps rather than small "plastic cable" clamps. Metal clamps serve as a heat sink.

POPULAR ELECTRONICS



+40

+30

+20

W m+10

o

-20 .2 .4 .6 .8 1.0 2 4

... I

... i _. .._

.. 01/ Im5Q powiwAidsem ew - nsi

11111 . mom v ̀' " ..lilii0 .: 4111111111101 paw ling __

IIIMM E1111 11111

ImC= ICIII

AC

What Are These Things Called Decibels? (oc- lober. 1966. page 76). The three heavy black rules on the "AC Volts To dB Graph" slipped out of registration in some copies of the Octo-

6 8 10

VOLTS

her issue. See corrected graph above. The "0 dB =1 mW in 600 -ohm" line should show 0 dB for 0.775 volts, and 28 dB for 20 volts. Space between the rules remains the same. 30-

20 40 60 80 100

HEAR POLICE, FIRE, AIRCRAFT, TAXIS on Your Transistor Broadcast Radio

DUAL CHANNEL

SINGLE CHANNEL Crystal -

controlled. Antenna extends to 36 inches.

$24.95 POSTPAID

It's Easy with the PRM VHF COMPACT CONVERTER

Has two crystal -controlled channels, with selector switch. Not to exceed 4 Mc. between frequencies.

$29.95 POSTPAID

Place it next to a good 7 -10 transistor broadcast radio, and you can monitor the VHF frequency specified. Performance of up to 20 miles or more under good conditions. Compact, portable. No internal connection needed. Case 2 -13/16 x 1 -5/8 x 4 inches. Pow- ered by 9-volt transistor battery. Current drain 3 Ma. at 9V. In ordering, specify VHF frequency desired, within these ranges: 148 -175 Mc., 25-50 Mc. AM or FM, and 108 -136 Mc. Give position of low activity on your broadcast dial. Price includes battery.

USE THIS PETERSEN RADIO CO., INC. 2800 West Broadway

COUPON Council Bluffs, Iowa 51501

TO ORDER Please send VHF COMPACT CONVERTERS as ordered below: Single Channel @ $24.95 each, Postpaid. To receive VHF Frequency Mc.; Broadcast Dual Channel @ $29.95 each, Postpaid. For VHF Frequencies Mc. and Mc. Broadcast frequency preferred Kc. Check or money order enclosed. (Or send C.O.D.)

Name Address

City State ZIP

PETERSEN RADIO CO., INC. 2800 West Broadway

Council Bluffs, Iowa 51501

December, 1966

Kc.

.1

89



The most experienced all- channel amplifiers keep getting better and better

Blonder- Tongue pioneered and developed the industry's first all- channel, all- transistor TV signal amplifier. That was more than two years ago. During that period this top -rated original design has brought superior all- channel and color reception to homes located in all reception areas.

Now, we are employing the better performing silicon transistor in these amplifiers. The result: 40% more gain in the lowband, 100% more in the highband, greater ability to handle strong signals without overloading and better signal to noise ratio. Color or black -and -white TV reception on any and all channels from 2 to 83 is better than ever.

Only Blonder- Tongue gives you a choice of all- channel, color -approved amplifiers: U /Vamp -2 - mast -mounted, deluxe 2- transistor UHF /VHF amplifier. Weatherproof housing. Remote power supply. AC operated. Separate UHF and VHF 300 -ohm inputs and outputs. Ideal for separate UHF and VHF antennas. Coloramp -U /V -same as the U /Vamp -2 except it has a single UHF /VHF input. Matches the new all- channel antennas. V/U -All -2 - deluxe 2- transistor indoor UHF/ VHF amplifier. Can drive up to 4 TV sets. Has built -in 2 -way splitter with excellent impedance match and isolation for interference and ghost - free reception.

These UHF /VHF amplifiers are just one more reason to go all- channel from antenna to TV with color- approved Blonder- Tongue TV products. Of course, we also have a full line of top quality VHF, VHF /FM and UHF -only amplifiers. Write for free catalog #74. Blonder - Tongue Laboratories, Inc., 9Alling St. Newark,N.J.


BINARY COUNTER (Continued from page 61)

preassembled circuit board to the readout lamps, push- button switches, and supply battery.

The IC's and the transistors can be mounted on insulated Teflon press -fit terminals as shown in the layout of Fig. 5, or on "flea" clips ( push -in terminals) if a perforated phenolic board is used. The use of regular 8 -pin IC sockets and 3- terminal transistor sockets will provide greater ease of assembly, and reduce the possibility of the solid -state devices being damaged due to overheating at the terminals.

The IC packages are coded by a flat side or a green or red dot indicating pin 8. When viewed from the top, the pins are counted counterclockwise.

Figure 5 shows IC4 mounted directly on one of the push buttons by means of a circular plate with feedthrough terminals, but you'll find it more convenient to mount IC4 on the same circuit board with the other units.

Switch S3 and the battery holder can be fastened to the case with #6 hardware, or can be pop- riveted in place. Switches S1 and S2 are mounted with hardware provided. The lamps are held by ',' " -o.d. rubber grommets mounted in the holes provided. If a dialplate is used, it can be secured to the cover with the mounting hardware for the push- button switches. A cross -section view of the assembled unit ( Fig. 6) shows mounting details of major components. Rubber feet can be attached to the container base.

Operation. Insert the batteries and flip the power switch to ON. With each de- pression of the COUNT push button, the binary count is advanced by one. To demonstrate binary addition, clear the binary counter to 000 with the CLEAR push button, and press the COUNT button to enter your first number. If it's a 2, enter binary 010 by depressing the COUNT push button twice. Now enter your second number. If it's a 3, enter 011 by pressing the COUNT push button three times. The answer 101 should appear on the readout lamps. 3

POPULAR ELECTRONICS



SMALL TAPE RECORDERS (Continued from page 52)

the mike, or pretend that the recorder is not working. Use the phony cord trick.

For instance, suppose some one asks you what's in that little box you are carrying. Don't hesitate to tell him it's a tape recorder. If he stops talking, pull a line cord out of your pocket and offer to show him how it works if you can find an a.c. outlet. As soon as he is convinced that the recorder is not working, he'll start talking again. What he doesn't know is that the machine is operating on batteries.

Voice Letters. Very often the written word can be misconstrued, but a tape of your voice with all its inflections, your laughing, or sobbing -which is really you by nature -will get through with full meaning. And a taped letter can become a group project, with comments and sounds of an entire household -truly a family letter.

Taped conversations in a barber shop, a beauty parlor, between a couple of friends meeting on the street, or between two motorists fighting for the same parking space, are vastly different from even a most vivid description of these events in a written letter. Chances are that once you get into the habit of taping letters, you will stick to it.

Other Applications. If you are a student, let your tape recorder do your note - taking so that you can concentrate on what is being said. When you get home, you can transpose your notes into writing if you have to. You can cut down your library time considerably if you have to transcribe reference works. Find a corner in the library where you won't disturb anybody, and read the works in- to your tape recorder.

You can also add another dimension to your home movie -making; just turn on your tape recorder (without telling anybody) and start shooting pictures.

From the busy executive on the go, dictating in a car, train, or plane, to the man on the street capturing the sounds of the town, the small tape recorder serves its purpose admirably. CAL-

December, 1966

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2 NEW AUTO TUNE UP INSTRUMENTS

DWELL TACH METER METER

$12.95 $14.95 Ppd. Ppd.

These two new cousins to the world famous proven MARK TEN now give you the capability to tune your own car inexpen- sively, easily, with remarkable precision. These separate instruments are low cost, portable and the easiest to read you've ever seen.

Delta's famous printed circuit design Superior in precision, quality and per-

formance to instruments selling for FIVE TIMES as much

Large dial, high quality jewel D'arson. Val meters

Operates with standard, transistor or capacitive discharge systems as well as magnetos

Instant readings - no confusing scales

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P.D. Box 1147 PE Grand Junction, Colo. Enclosed is $ . Ship prepaid. El Ship C.O.D. Please send: 0 Dwell Meters 4, $12.95

Tach Meters (a $14.95 171 Mark Tens (Assembled) @ $44.95 El Mark Tens (Delta Kit) $29.95 (12 volt positive or negative ground only)

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STEP UP YOUR INCOME Learn at Home to Fix ELECTRICAL APPLIANCES If you have a business or job in Radio -TV Servicing or other home service, you'll find Electrical Appli- ance Repair a natural, profitable addition. NRI trains you quickly in spare time, shows you how to add to your income long before you finish training. NRI gives you parts to build your own Appliance Tester. Learn how to repair small and large appliances plus air conditioning, refrigeration, small gasoline engines, equipment used on farms and commercially. Cash in on this money- making side- line. Mail coupon for catalog. No obligation. NATIONAL RADIO INSTITUTE, Appliance Div., Wash- ington, D.C. 20016

Training Available Under New GI Bill

FREE CATALOG

MAIL COUPON - NATIONAL RADIO INSTITUTE Washington, D.C. 20016 Please send me your Electrical No salesman will call.

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Striking contemporary art frame design in Dusk Walnut or Antique Birch. Mount traditionally or in diamond position. Special 8" dual cone speaker designed exclu- sively for Argos. Excellent for stereo or as extension speakers. Audiophile net $12.95.

Great gift idea!

?rnuóadar model TSW -8S by

92

[1P OS PRODUCTS COMPANY

Dept. C, 600 Sycamore St., Genoa, Illinois 60135


TAPE RECORDER KIT- DELUXE (Continued from page 66)

tape transport is too big a job for the electronics technician. But you may not know that a high percentage of tape recorders use a single motor. That motor must be linked up to perform the functions of rewind, drive, and fast forward. The Heathkit AD -16 uses three separate synchronous motors and each does just one job. Linkages and drive belts are few and far between in the AD -16.

To further elimin t e the complexity that you see in some tape transport mechanisms, the AD -16 is all- solenoid- operated. You push a button on the front panel and the solenoid plungers do all the work- starting and stopping the tape, lifting tape off heads, etc.

How Good Is Good? If you have never heard a good tape played back on a good tape recorder, words are not adequate devices to insure a good description. About the best we can do without re- sorting to hyperbole and superlatives is to mention the dynamic range and obvious purity of sound.

A tape recording is much, much closer to an original performance than even the very best disc recording -and, by the way, tapes are not gimmicked like the recordings of most major record companies. There's no reason to add distortion to compensate for distortion when you play nothing but tapes.

The AD -16 lets you hear everything on the tape just as perfectly as when it was recorded. 30

"Instead of four 50 -ohm resistors, I gotcha one 200- ohm -it was much cheaper."

POPULAR ELECTRONICS



LOGIC DEMON

(Continued from page 45)

button. In the OR function, the bulb lights when either push button is de- pressed, while in the AND function, both push buttons must be pressed at the same time for the light to come on. With the switch in an NAND position, both push buttons must be simultaneously pressed to put out the light.

The Logic Demon can be used in a classroom or at a Science Fair to demonstrate the practical application of computer (symbolic) logic. Granted that a number of individual switches could be used to perform the same function as the single IC package, it can be seen that the use of integrated circuits greatly simplifies the project. The Logic Demon also demonstrates some practical applications of the use of integrated circuits in computer technology. -o-

"RELAXATROL" (Continued from page 56)

bly. Slip a piece of spaghetti over each of the leads to insulate them and prevent short circuits.

Exercise care and work slowly when drilling holes in the plastic case. Use a file to shape the opening for the switch. A bottom cover for the case can be made from a thin piece of plastic or stiff cardboard, if you don't already have one. Two precautions should be taken : observe polarity of the diodes or proper connections of the rectifier module; and don't compromise the insulation -the rectifiers and S1 are connected directly to the a.c. line.

Operation. When the unit is completed, check the wiring for any errors, then secure the bottom cover. Plug the a.c. line cord into a wall outlet and switch on the unit. After a slight delay, the relay should pull in and out at a regular interval. Rotate R2 to change the interval. Range should be from very fast (approximately 15 seconds) to very slow (approximately 2 minutes). If desired,

HOW GOOD IS A

TEENY WEENY CARTRIDGETIM

Great! /Full stereo separation even at 15,000 cps. /4 poles, 4 coils & 3 magnets for better balance & phe- nomenal frequency response /Fully shielded /Lowest 1M distortion (electro -sheer suspension)/ Highest output (8 Mv. per channel) /Lowest tracking for longer record wear. Write for 1967 color brochure. EMPIRE LIVING CARTRIDGE SERIES FROM 814.95. Empire Scientific Corp., 845 Stewart Ave.,Garaen City, L.I., New York 11530


NEW 514 -PAGE

411 /ED 1967 CATALOG

Top Savings on the best in electronics for everyone... Famous Knight -Kits Stereo Hi -Fi Tape Re-

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ALLIED RADIO, Dept. 3M P.O. Box 4398, Chicago, III. 60680

Send FREE 1967 Allied Catalog

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AM /FM VHF RECEIVERS POLICE FIRE AIRCRAFT

AMATEUR GENERAL COVERAGE

The new 3648 is a completely self contained highly sensitive receiver offering the user continuous AM /FM coverage from 26 to 54 and 88 to 174 MC in eight bands. Features: superhet circuitry, full vision calibrated dial with vernier drive, speaker, power transformer, ready to use for 110/120 V AC.

364Eì

$49.95 348A Transistorized tuneable converter for use with car, home or portable radio. Ranges: 30 -50, 115 -130, 150 -162 MC. Bat. incl. Same but crystal controlled for 12 V car use. (345A) $29.95. Economy tuneable model (315T) same ranges $18.95

348A

$34.95 361C AUDIO EQUALIZER

$4495 Variable equalizer necessary for professional quality recording or playback. Ideal for use between mixer and tape recorder or tape to tape, etc. Write for details or send $2.00 for LP demonstration record. Covers tape and disc recording techniques. Refunded with purchase.

Order direct or write for information

KUHN ELECTRONICS 20 GLENWOOD CINCINNATI 17, OHIO


SAY YOU SAW

IT IN

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SMALL,

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INTRODUCING... the NEWEST sod most ECONOMICAL MODEL et the

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the time intervals can be marked on a dialplate placed under the control knob.

Connect the push- button leads from the projector to PL1 through a mating socket. Use a small caliber plug and socket for this purpose to prevent confusion with the a.c. line cord. Set up your projector as usual, and allow the Relaxatrol to go to work. If you want to view a particular slide for a longer period of time, simply turn the unit off until you are ready to start again. If you want to quickly dispose of a slide without upsetting the timing sequence, hit the push button just once.

You can shift the range of speeds by using a smaller or larger resistor in place of R1 or by changing value of C2.

THE "SCROUNGE" (Continued from page 46)

You could hang this antenna from a tree, or -if you want to get fancy -substitute aluminum or copper tubing, but maintain the same dimensions. If you support the lower part of the antenna with insulated standoffs, you'll have a first -class permanent installation.

If you hang the antenna from a tree or other high structure, you can reverse the connections to the coaxial cable to provide for some degree of lightning protection. With the leads reversed, the highest point of the antenna will be connected to the coaxial cable's shield, which is usually grounded at or near the equipment. Antenna action is not ma- terially affected by this reversal because the quarter -wave section acts like a transformer.

As with any antenna work, there is no substitute for actual on- the -job tuning, adjusting, and other optimizing activities. The figures shown are close enough for most applications, and include some consideration for end effect. If you want to experiment using a cut -and -try technique, you can first try shortening the quarter -wave section about 1 /2" at a time before modifying the half -wave section. Telescoping sections such as are found on a pair of TV "rabbit ears" could help you pin down the exact dimensions. -ice

POPULAR ELECTRONICS



Regardless Of What You Pay For A 19" Color TV...

It Can't Perform As Well As This

New Heathkit "180" For Only $37995*

Here's Why! Exclusive Features That Can't Be Bought In Ready - Made Sets At Any Price! All color TV sets require periodic convergence and color purity adjustments. This new Heathkit GR -I80 has exclusive built -in servicing aids so you can perform these adjustments anytime ... without any special skills or knowledge. Simple -to- follow instructions and detailed color photos in the GR -180 manual show you exactly what to look for, what to do and how to do it. Results? Beautifully clean and sharp color pictures day in and day out ... and up to $200 savings in service calls during the life of your set!

Exclusive Heath Magna -Shield ... surrounds the entire tube to keep out stray magnetic fields and improve color purity. In addition, Automatic De- gaussing demagnetizes and "cleans" the picture everytime you turn the set on from a "cold" start.

Choice Of Installation ... Another Exclusive! The GR -180 is designed for mounting in a wall or your own custom cabinet. Or you can install it in either optional Heath factory -built Contemporary or Early American styled cabinets.

From Parts To Programs In Just 25 Flours. All critical circuits are preassembled, aligned and tested at the factory. The GR -I80 manual guides you the

rest of the way with simple, non -technical instructions and giant pictorials. You can't miss! Plus A Host Of Advanced Features ... like the hi -fi 180 sq. inch rectangular tube with "rare earth phos- phors", smaller dot size and 24,000 volt picture power for brighter, livelier colors and sharper definition ... Automatic Color Control and gated Auto- matic Gain Control to reduce color fading and insure jitter -free pictures at all times . . . deluxe VHF Turret Tuner with "memory" fine tuning ... 2 -Speed Transistor UHF Tuner ... Two Hi -Fi Sound Outputs for play through your hi -fi system or connection to the GR -180's 4" x 6" speaker ... Two VHF Antenna Inputs - a 300 ohm balanced and a 75 ohm coax ... I -Year Warranty on the picture tube, 90 days on other parts. For full details mail coupon on the following page. Better yet, use it to order the best 19" Color TV buy ... it's available now in limited quan- tities. *Kit GR -180, everything except cabinet, 102 lbs $379.95 GRA- 180 -1, walnut cabinet (shown above), 30 lbs...18'%" D x 28'/4" W x 29" H.. $49.95 G RA-180-2, Early American cabinet, 37 Ibs ...183/4" D x 28'/4" W x 313/4" H. Available February $75.00

NEW 12" Transistor Portable TV - First Kit With Integrated Circuit Unusually sensitive performance. l'lays anywhere ... runs on household 117 v. AC, any 12 v. battery, or optional rechargeable battery pack ($39.95); receives all channels; new integrated sound circuit replaces 39 components; preassembled, prealigned tuners; high gain IF strip; Gated AGC for steady, jitter -free pictures; front -panel mounted speaker; assembles in only 10 hours. Rugged high impact plastic cabinet measures a compact 11' h" H x 153/4" W x9 /a "D.271bs.

Kit GR -104

$1 1 995

Turn Page For More New Kits From HEATH CIRCLE NO. 18 ON READER SERVICE PAGE

December, 1966 95



9 Kit - Giving Ideas From Heath... Harmony -by- Heathkit ®Electric Guitars & Heathkit Guitar Amplifier

A 4 Kit TG -26

Ì Kit TG -36

$9995 $11995 (save $46) (save 338.55)

Kit TA -16

$12995

NEW Heathkit Transistor Guitar Amplifier 60 watts peak power; two channels - one for ac- companiment, accordian, organ, or mike, - the other for special effects ... with both variable reverb and tremolo; 2 inputs each channel; two foot switches for reverb & tremolo; two 12" heavy -duty speakers; line bypass reversing switch for hum re- duction; one easy -to -build circuit board with 13 transistors, 6 diodes; 28" W. x 9" D. x 19" H. leather -textured black vinyl cabinet of 3/4" stock; 120 v. or 240 v. AC operation; extruded aluminum front panel. 44 lbs.

American Made Harmony -By- Heathkit Guitars All guitars include instruction book, tuning record, pick, connecting cord, deluxe red leather cushioned neck strap and chipboard carrying case. All wood parts assembled and factory finished - you just mount metal parts, pickups & controls in pre -drilled holes and install strings.

© Deluxe Guitar ... 3 Pickups ... Hollow Body Double- cutaway for easy fingering of 16 frets; ultra -slim fingerboard - 241/2" scale; ultra -slim "uniform feel" neck with adjustable Torque -Lok

reinforcing rod; 3 pickups with individually adjustable pole - pieces under each string for emphasis and balance; 3 silent switches select 7 pickup combinations; 6 controls for pickup tone and volume; professional Bigsby vibrato tail -piece; curly maple arched body - 2" rim - shaded cherry red. 17 lbs.

© Silhouette Solid -Body Guitar ... 2 Pickups Modified double cutaway leaves 15 frets clear of body; ultra -slim fingerboard - 241/2" scale; ultra - slim neck for "uniform feel"; Torque -Lok adjustable reinforcing rod; 2 pickups with individually adjustable pole -pieces under each string; 4 controls for tone and volume; Harmony type 'W' vibrato tailpiece; hardwood solid body, 11/2" rim, shaded cherry red. 13 lbs.

11 "Rocket" Guitar ... 2 Pickups ... Hollow Body

Single cutaway style; ultra -slim fingerboard; ultra - slim neck, steel rod reinforced; 2 pickups with individually adjustable pole - pieces for each string; silent switch selects 3 combinations of pickups; 4 controls for tone and volume; Harmony type 'W' vibrato tailpiece; laminated maple arched body, 2" rim; shaded cherry red. 17 lbs.

NEW! Deluxe Solid -State FM /FM Stereo Table Radio

Tuner and IF section same as used in deluxe Heathkit transistor stereo components. Other features include automatic switching to stereo; fixed AFC; adjustable phase for best stereo;

Kit GR -36 two 5'/4" PM speakers; clutched volume control for individual channel adjustment; compact 19" W x 61/2" D x 91/4" H size; preassembled, prealigned "front- end "; walnut cabinet; simple 10 -hour assembly. 17 lbs.

$6995




Something For Everyone NEW Heathkit® /Magnecord® 1020 4 -Track Stereo Recorder Kit

Kit AD -16

$39950 (less cabinet)

Save $170 by doing the easy assembly yourself. Features solid -state circuitry; 4 -track stereo or mono playback and record at 71/2 & 33/4 ips; sound -on- sound, sound- with -sound and echo capabilities; 3 separate motors; solenoid operation; die -cast top -plate, flywheel and capstan shaft housing; all push- button controls; automatic shut -off; plus a host of other professional features. 45 lbs. Optional walnut base $19.95, adapter ring $4.75

NEW Deluxe SB -301 Amateur Receiver Kit NEW Deluxe SB -401 Amateur Transmitter Kit

Kit SB -301

$26000 (less speaker)

New SB -301 receiver for 80 thru 10 meters with all crystals furnished, plus 15 to 15.5 MHz coverage for W W V ; full RTTY capability; switch -selected ANL; front -paneling switching for control of 6 and 2 meter plug -in converters; crystal -controlled front -end for same rate tuning on all bands; 1 kHz dial calibrations, 100 kHz per revolution. 23 lbs. Matching SB -401 Transmitter, now with front -panel selection of independent or transceive operation... $285.00

2 -Watt Walkie -Talkie Assembled GRS -65A

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HEATHKIT 1967 FREE World's Largest

Electronic Kit

December, 1966

Catalog! 108 pages ... many in full color ... describe these and over 250 easy -to -build Heathkits for color TV, stereo/ hi -fi, CB, ham, marine, shortwave, test, educational, home and hobby items. Mail coupon far your free copy.

NEW Portable Phonograph Kit Kit GD -16

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All Transistor. Assembles in 1 to 2 hours. Preassem- bled 4 -speed automatic mono changer; 4" x 6" speaker; dual Sapphire styli; 45 rpm adaptor; olive & beige preassembled cabinet; 117 v. AC. 23 lbs.

HEATH COMPANY, Dept. 10.12

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(In Mobile Installations) Only the Squires- Sanders Noise Silencer eliminates noise caused by ignition, power lines, etc. Only two transceivers have this exclusive feature -the Squires- Sanders "23'er" with full 23- channel capability (all crystals supplied) at $235 and the "S5S" 5- channel model at $185. Other features include an ultra - sensitive receiver and a powerful, long -range transmitter (special high efficiency RF output amplifier clipped and filtered audio, 100% modulation). 12 VDC power supply. Squires- Sanders Inc., Millington, N. J. 07946.

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98

ON THE CITIZENS BAND


"Thatman and Who ?" We were minding our own business, coming out of an electronics center after having made a purchase, and to our surprise found half -a -body hanging out of our sports car window, clad in a pair of tights and some very "different" looking shoes. The other half of the body projected into the interior of the car. On closer inspection through the windshield, we found the top half of the mysterious figure clad in a tight jersey, a pretty sharp looking cape, and (of all things) a black mask.

The gent emerged to inform us that he had become interested in our two -way CB gear under the dash. He then asked an assortment of questions on how CB'ers operate, the type of communications we become involved in, and the main purpose of the system. We were happy to oblige (see photo below).

In the middle of our discussion on the useful application of CB radio to emergency situations (he seemed very impressed, inci- dentally), a sleek, highly powerful looking black automobile( ?) drove up alongside to pick up my friend. The driver of the vehicle was similarly clad in an assortment of close -fitting garments, but sported a hood and a large flowing cape, and the car itself was loaded with all sorts of devices, controls, and gadgets. Indicating that my

Photo by James Karr

POPULAR ELECTRONICS



friend should get in quickly, he mumbled something about a caper.

As the pair went off in a puff of exhaust, we thought we faintly heard them enthusi- astically exchanging a series of words like: "Biff- Pow- Wup -Hmm . . . " Sometimes people make you wonder, boy!

Club News. The Western New York Pio- neer Citizens Band Association, North Ton- awanda, N.Y., reports that its Third Annual CB Jamboree was extremely successful. The event was held for the benefit of handi- capped and retarded children, with monies raised to be distributed among area children's homes.

Honored guests of the day were 70 children from St. Rita's Home For Retarded Children. The children were brought to the jamboree by buses supplied by the Pioneer CB Club, and were escorted by 36 adults from St. Rita's who watched over them during their three -hour visit. They were treated to dinner, cotton candy and liquid refreshments, plus rides on the midway.

At the jamboree, the publicity director of the Pioneers, Vernon W. Batt, KIC5311, supervised the presentation of a bound copy of the June, 1966, issue of POPULAR

Photo by M Sheen

ELECTRONICS to Lockport, N.Y., Mayor Roland T. Grant by James Trombino. (The Pioneer CB'ers had been praised in the OTCB column that month for their fund- raising activities.) Vern reported that the one -day affair realized a profit of approximately $4000 to aid needy children.

In the week following the jamboree, the Pioneer membership approved the purchase of a tape recorder, slide projector and screen, and a 35 -mm. camera, to be presented to St. Rita's Home. The officers and members of the club extended their sincere thanks to all persons involved with the jamboree, in addition to the following CB clubs that gave both personal and financial aid: Grape Belt CB Club, Dunkirk, N.Y.; The W.N.Y. Frontiersmen CB Club, Lockport, N.Y.; The Niagara Nuggets CB Club, Buffalo, December, 1966

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CIRCLE NO. 34 ON READER SERVICE PAGE J

99



POPULAR ELECTRONICS SUBSCRIBER SERVICE

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1967 OTCB Club Roster. If your group was not placed on the 1966 OTCB roster of active associations across the U.S. and Canada, gather up the statistics and ship them off to us soon -in time for the first 1967 listing. Specify membership totals and club officers; detail recent public service assists and activities; and be sure to forward your club paper as soon as it's published. Include some photos of your group and a club decal and or membership card, and we'll try to show them to the rest of our CB readers.

I'll CB'ing you! -Matt, KHC2060

BRIDGE CIRCUIT QUIZ ANSWERS

(Quiz appears on page 73 )

1 - J The CAREY FOSTER bridge measures capacitance in terms of mutual conductance, and mutual conductance in terms of capacitance.

2 - H The HAY bridge measures the self - inductance of high -Q coils (Q greater than 10), and also determines unknown frequencies.

3 - D The HEAVISIDE bridge measures the mutual inductance of the coils of a transformer in terms of a known self - inductance and known resistances.

4 - I The K=LVIN bridge is used when ex- trem.ly low resistances -down to 0.001 ohm -are to be measured.

5 - C The MAXWELL bridge measures the self- inductance of low -Q coils (Q of 10 or less).

6 - F The OWEN bridge, like the HAY and MAXWELL bridges, measures the self - inductance of coils. The main difference between the OWEN and the other two bridges is that the OWEN bridge has the two adjustable components in the same arm.

7 - A The RESONANCE bridge measures capacitance, inductance, and frequency.

8 - G The SCHERING bridge measures capacitance in terms of a standard capacitor and known resistances.

9 - B The WHEATSTONE bridge, oldest of the bridge family, is used where accurate resistance measurements -in the range of 1 ohm to approximately 1 megohm -are to be made.

10 - E A WIEN bridge is used to measure capacitance by comparison with a

standard capacitor, and inductance by comparison with a standard in- ductor.




AMATEUR RADIO


NEWS AND VIEWS

Louis Laukich, WA /WN8SNF, 107 7th St., N.W., Barberton. Ohio, works 40 -meter CW and 2 -meter phone with a rebuilt Knight -Kit T -150A transmitter. He receives on a Knight -Kit R -100A (aided by a Vanguard converter for "6"), and the out- door work is handled by a 40 -meter inverted -V antenna. a 24' home -brew vertical antenna. and a 6 -meter beam. There are 35 states logged on Lou's "brag sheet." . SP /4 John W. Good, Jr., K3SIO /HS1, U.S. Army Satcom Station. APO, San Francisco, Calif., says there is no VHF or UHF amateur activity within 500 miles of Bangkok; so he spends most of his time building and testing gear. His latest creation is a 6 -meter receiver with a 6 -dB signal- plus -noise to noise ratio at a -124 dBm signal. His next project is to "scrounge" some 1296 -MHz gear. John can be heard on the Southeast Asia net on 14.322 MHz at 1200 GMT using an SBE- 34 exciter, a 1000 -watt amplifier, and a Telrex tri -band beam . K3SIO reports that Don, WA8OBB /XV5, Cam Ranh Bay. Vietnam, is also active on 14 MHz with a Drake TR -4 and a 1/2-wave dipole antenna.

Alexandre Ermine, TAQ3RXTX, Izmir, Turkey, studies electronics in the daytime and works in a radio shop at night. He would like to exchange letters with U.S. amateurs about getting on the air. Address letters c/o A3C Delbert Stout, AF- 17701793, TUSLOG Det. 118, C.M.R. Box 342, APO, New York 09016. . Dan Taylor, ex- WB6PJK, c/o Ron Davis, 3907 Shadyhill Dr., Dallas. Texas, had rather an odd record while a Novice in Covina, Calif. Using a 5 -watt, home -brew transmitter, he made 300 contacts -all in California -on 80 meters. Then with a 40- waiter, he worked 10 states. When he became a General, a Johnson "Challenger" transmitter feeding a vertical antenna racked up 40 states and five countries. We don't know what Dan's new "5" call letters are ... Jim Rembiszewski, WN9SIK, R.R. #3, Box 83A. Antigo, Wis., found out "the hard way" that the pi -net output tank circuit of a transmitter won't match just any old antenna. But his Knight -Kit T -60 transmitter and 321/2' home -brew vertical antenna get along well on 40 meters. The antenna is constructed of 14" conduit and is fed with 52 -ohm coaxial cable. Jim receives on a Knight -Kit R -55A. He has worked 13 states so far, and two Canadians.

Landon L. Chapman, W4VTU, 204 Sunset St., Bristol, Tenn., and his local radio club are offering a QSO Award to amateurs who work five Tennessee amateurs (25 if you live in Tennessee). You can

get the details from Landon for a stamped reply envelope. He will also answer questions about amateur radio for truly interested people. W4VTU works the lower frequencies with a Johnson "Ranger" transmitter and a Hammarlund HQ -110A receiver. For 2 meters, a war -surplus ARC -4 transmitter feeding a beam antenna and a converter ahead of the receiver do the work. He has a wall full of QSL cards to prove that he doesn't talk to himself . . . Mike Czuhajewski, WA8MCQ, Route 3, Paw Paw, Mich.. believes that he worked a "KZ5" on the 80 -meter Novice band in broad daylight recently. We hate to disappoint Mike, but we suspect that he worked a "bootlegger" in the neighborhood. Happier news: Mike found that adding radials to his Hy -Gain 18V antenna allowed him to work three W6's in a row on 40 meters. Before making the change, he had worked one "6" out of 1143 contacts . . . Red Rowcliffe, WA6QMU, 6271 Merced Lake Ave., San Diego, Calif., makes certain that recipients really look at his QSL card. It is a very attractive color photo of him and his station, with the call letters occupying a 1 x 14á" space in the picture. Red (who is former KOKOA) uses a Collins 3253 driving a 30L1 amplifier into a Hy -Gain TH -3 rotary beam 70' high and a Collins 75S -3B receiver. Besides being good -looking, the equipment must work well, because Red keeps regular traffic schedules with KR6USA on Okinawa.

Joe Patrick, WN3FDT, R.D. #4, Box 104, Finley - ville, Pa., uses a 35 -watt transmitter built by WA3CWD. It shares time with a Hallicrafters SX -101A receiver on a 24' high, 40 -meter inverted - V antenna. In six months of 40 -meter operation, Joe has eight pages of contacts scattered from coast to coast . . If you should run across Howard Pyle, W7OE, and Lew, W7APS, sending "crazy" CW on 3540 kHz, think nothing of it. They are using "land -line" Morse code. Join them if you can send and receive the stuff. Thanks to the 7th Call Letter District QRP Amateur Radio Club Bulletin for this information . Dave "Top" Harmacek, WN8TOP, 8364 Lincoln Drive, Chesterland. Ohio, knocked off 23 states and Canada his first five weeks on the air. An EICO 720 transmitter feeding dipole antennas and a "homemade" (yep, that's what the man said) Mosley CM -1 receiver on the 40- and 80 -meter bands did the work.

Before we hit the bottom of the page, let us say "Merry Christmas and Peace on Earth" to all. If your chimney is too small for that new gear you asked for, leave the door unlocked. As always, we remind you that the first step towards representa- tion in your column is mailing us your "News and Views" and photographs. Keep those club bulletins coming; and please let us know if you or your club conducts on- the -air code practice. The address is Herb S. Brier. W9EGQ, Amateur Radio Editor, POPULAR ELECTRONICS, P. O. Box 678, Gary, Ind. 46401.

73, Herb, W9EGQ

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NO. 36 ON READER SERVICE PAGE 101



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SHORT -WAVE LISTENING (Continued from page 81)

Brazil. The station is currently operating on ZYR44, 9635 kHz, and ZYR89, 3285 kHz.

Trans World Radio, Bonaire, Netherlands Antilles, now has a DX program for North American listeners on Fridays at 1205 on 11,820 kHz; for Europe on Saturdays at 0200 on 15,245 kHz; and another broadcast on Sundays at 0335 on 11,815 kHz. Al Stew- art is in charge of the program.

Over the past three years, a number of DX'ers have asked us to help them identify the singer of the "Kiss Me Honey" record that, until recently, was the one and only recording of the Kiss Me Honey station on 11,695 kHz. (It has been changed to "Can't Buy Me Love," recorded by the Beatles.) The singer is Miss Shirley Bassey, and the record is an LP issued by Phillips of Aus- tralia in the "Party Dance Series," number PD29. The orchestra is believed to be that of Tony Osborne.

Mr. C. E. Chicarelli of the Anglo -Thai Corp., Ltd., states that Radio Thailand is now using an RCA "Ampliphase" 100 -kW transmitter with a horizontal rhombic antenna beamed at N. A. over the North Pole. Current operations are on 11,910 kHz "most of the day with programs in Thai, French, and English." They are anxious to receive detailed reception reports from N. A., which should be sent to Thailand Overseas Broad- casting Station, Rangsit, c/o Public Relations Department, Rajadamnern Ave., Bangkok, Thailand. Mr. Chicarelli is in the Com- munications and Engineering Department.

CURRENT STATION REPORTS

The following is a resume of current reports. At time of compilation all reports are as accurate as possible, but stations may change frequency and/ or schedule with little or no advance notice. All times shown are Greenwich Mean Time (GMT) and the 24 -hour system is used. Reports should be sent to SHORT -WAVE LISTENING. P.O. Box 333, Cherry Hill, N.J., 08034, in time to reach your Short -Wave Editor by the fifth of each month; be sure to include your WPE identification, and the make and model number of your receiver. We re- gret that we are unable to use all the reports received each month, due to space limitations, but we are grateful to everyone who contributes to this column.

Ascension Island -Look for the new service from the BBC relay station here at 2300 -0215 beamed to South and Central America. This xmsn, on 15,375 kHz, is a relay of the BBC Latin American service.

Bermuda- DX'ers needing a QSL from this country should tune to the medium -wave outlet on 1235 kHz for ZBM1, Hamilton. While on a split channel between two "graveyard" frequencies, the station is often noted well in Eastern areas around 0500. A report with an IRC brought a prompt QSL.

Bolivia -R. Am boro, Santa Cruz de la Sierra, has been noted once again on 4898 kHz (varies) and announcing as 4915 kHz. Signal is very weak.

POPULAR ELECTRONICS



Latin American pop tunes are featured; there are a few ID's; and closing is around 0200.

Burma -The 5040 -kHz outlet has been heard as early as 1115 -1155 with Burmese music and what appears to be a newscast at 1146.

Cambodia -Phnom -Penh has a new frequency. 4910 kHz, for the Home Service, noted at 1230 -1245 in French, at 1245 with Eng. news, and dance music with anmts in French at 1300 and 1330.

Canada -Those who have CBC schedule #56 should change the frequency of 11,725 kHz in the Caribbean and Latin American Service at 2258- 0046 to 11,760 kHz.

Colombia -A new or "misplaced" station being heard on 6020 kHz is definitely Colombian and is located in Bogota. Check for it around 0230.

Station HJFW, Transtni.sora Calcios, Manizales. has moved up from 5020 tu 5025 kHz. where the signal is much weaker. This may be a standby xnttr in use while the main one undergoes maintenance. Do not confuse with the Euadorian on 5023 kHz.

A new outlet is R. Nacional de Colombia on 15.- 325 kHz. Noted all day, it runs "dual" to 3290. 4955. and 6180 kHz with the sanie programming, 'nchrding "English By Radio" from the BBC at 2345. S /off varies from 0400 to 0500.

SHORT -WAVE ABBREVIATIONS an nit -Announcement kHz -Kilohertz BBC- British Broadcast- kW- -Kilowatts

inn Corporation N.A. North America CBC- Canadian Broadcast - Q1,01 Station interference

inr Corporation QSL -Verification Eng. English R. -Radio I I1 -identification s off Sign -off IRC- International Reply on -Sign -on

Coupon mirini- Transmission IS -Interval signal astir Transmitter

Newcomer Kevin Drost, of Union Lake, Mich., has

already logged 30 countries -with a Hallicrafters SX -71 receiver -and has QSL's from 11 of them.

R. Santa Fe, Bogota. is widely reported from 0000 s /on to 1000 s /off on 4965 kHz, all- Spanish, with frequent and clearly understood ID's.

El Salvador- Station YSS. R. Nacional, San Sal- vador, reads all reports over the air in a special program called "Reports From Around The World" in Spanish on Sundays at 2330 and Mon- days at 0100. This station transmits on 6010 and 9555 kHz at 1700 -0500 with 5 kW.

Germany (East) -R. Berlin International has been logged on a new frequency of 17.880 kHz at 1650 in native language.

Haiti -Station 4VEH. Box 1. Cap Haitien, has been heard at 1211 with public service anmts in Eng., religious programming, and ID's on 9770 kHz. English is scheduled daily at 1130 -1430, on Saturdays at 1130 -1500, and on Sundays at 1130 -1500

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CIRCLE NO. 41 ON READER SERVICE PAGE December, 1966 107



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TED D USEFUL TOOL, ABSORBING HOBBY

RADIO is not only a useful tool for business and personal use, but can also be an enjoyable leisure time activity. Licensed radio amateurs partake in the full range of radio's fascinations with the encouragement of the Federal Communications Commission - Emergency and CD work, message relaying, building, designing, experimenting, modifying, DX chasing, contests and even ragchewing. THE mysteries of radio theory melt away, the erratic rhythms of Morse code begin to make sense when you base your study for an amateur license on the GATEWAY TO AMATEUR RADIO, a series of four booklets published by the hams' own society.

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The Radio Amateur's License Manual P12 Operating an Amateur Radio Station

X2OO Learning the Radiotelegraph Code How to Become a Radio Amateur

Name

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and 19U0- 2U30. Other frequencies in use are: 11,835. 6120. 2450, and 1035 kHz. Reports are requested from regular monitors; write to the address given above or to 466 Weaver Road, Webster, N.Y.

Haute Volta- Ouagadougou, 4815 kHz, opens at 0600 in French with Balafon IS and dance music to 0635, then news. This s /on time was confirmed in a QSL.

Honduras- Station HRVC, La Voz Evangelica de Honduras, Tegucigalpa, 4820 kHz, has a program in Eng. called "Songs In The Night" from 0300 to 0330 s /off on Mondays. Normal s /off other days is 0300. This station is heard best on Mondays because XEJG, Mexico, is off the air then.

Hungary-R. Budapest opens in Eng. at 0030 on the seldom -heard frequency of 9540 kHz, dual to the N. A. program on 11,910 kHz. The latter has also been noted with a repeat of the same program at 0130.

Indonesia -Sorong, 3335 kHz, was caught in In- dom'sian at 1255 -1300 with female speaker and piano recitals. Another female gave the news at 1300 after four time pips.

Japan -A new frequency for Nippon Hoso Kyokai, Tokyo, is 9670 kHz. It was observed at 1645 in Eng. with broadcast beamed to Africa.

Korea (North) -Pyongyang was noted on 7580 kHz in Eng. at 1141 -1210 but QRM prevented good readability. A new or different Russian broadcast now open at 1300 with an anthem; listed s /on times are 0300. 1000, and 1800. Another opening, with a 7 -note IS on an instrument resembling an organ. is at 2335; this xmsn, in Spanish, is on 14,510 and 11,750 kHz -no Eng. noted.

Lebanon -R. Lebanon, Beirut. has the following schedule in effect: to Africa daily on 15,350 kHz in Eng. at 1830 -1900, in Arabic at 1900 -2000 and in French at 2000 -2030; to South America daily on 15,325 kHz in Portuguese at 2300 -2330. in Arabic at 2330 -0030 and in Spanish at 0030 -0100; to N. A. daily on 11,760 kHz in French at 0130 -2000. in Arabic at 0200 -0230, in Eng, at 0230 -0300, in Arabic at 0300 -0330 and in Spanish at 0330 -0400. Omni- directional xmsns are broadcast daily at 0430 -0730 and 1415 -1820 on 5980 kHz and at 0930 -1400 on 9545 kHz.

Malagasy -Tananarive, 7105 kHz, was noted with Network II French at the odd time of 1410 to 1435 fade, with pop and dance music. Best day to log this one is Sunday, when schedule runs through from 0400 to 1930.

Malawi -Blantyre, 3380 kHz, was heard from 0359 to 0425 fade; drums IS to 0400, then a cock crowing and a native -language anmt, followed by news in native language at 0415.

Malaysia -R. Malaysia has a relay of BBC news

Two receivers are in use in the shack of H. Charles Fanjul, Jr., WPE4IVC, Miami, Fla. -a Lafayette HA -230 and a Heath GR -64. His record to date is 15 countries (10 verified), 4 states (verified).

POPULAR ELECTRONICS



SHORT -WAVE CONTRIBUTORS

Roger Camire (II'PEIGEK), Manchester, N. H. William Read (B'PEIGTG), South Hadley Falls,

Mass. William Graham (!t'PE2LIIIU), Binghamton, N. V. Frank Mather (WPE2LIIIV), Buffalo, N. Y. Kenneth Cohen (It'PE2LZJ), Woodbridge, N. J. C. N. Coombe (WPE2.IIOB), Trenton, N. J. Alan Coles (It PE2.VUI "), Leonia, N. J. Bernard Kinahan, Jr.. (WPE2OEE), Yonkers, N. Y. Bill Hafner (II'PE20JJ), West Islip, N. Y. John Zapisek (WPE2OKD), Wading River, N. V. Sherman Klem (WPE2OKL'), North Merrick. N. Y. Steve Milovich (WPE2OSC), Buffalo, N. Y. Clifford Mass (WPE2OWIJ'), East Meadow. N. Y. Ed Kowalski (11'l'E3AK), Philadelphia, Pa. Bob Huber (11'PE3GU,Y), Wilmington, Dei. Grady Ferguson (ll'I'E4BC), Charlotte, N. C. Bruce Churchill (IVPE4EI'D), Chula Vista, Calif. Kenneth Alyta, Jr. (ll'PE4FXB), Charlotte, N. C. Russ Steinke (WPE4IOK), Birmingham, Ala. David Meisel (WPE4IRS), Charlottesville, Va. Paul Judkins (WPE41S0), Herndon, Va. John Faulk (B'PE4JCF), Tucker, Ga. Douglas Gwyn (WPE5ASZ), Pasadena, Texas Stewart Mac Kenzie (l4'PE6AA), Huntington Beach.

Calif. Shaler Hanisch (fl'PE6BP.V), Pasadena, Calif. Trevor Clegg (WPE6FAF), Fresno, Calif. Mike Lombardi (WPE6GJIV), Lynwood, Calif. Mike Craig (WPE6GPA), Tustin, Calif. Robert Eddy (WPE8EQB'), Newport, Ohio Robert French (WPESFGH), Bellaire, Ohio Greg Bovee (WPESJAC), Rochester, Mich. Robert Wright, Jr. (WPE8JCF), Brighton. Mich. Carl Durnavich (It'PE91F0), Riverdale, I11. A. R. Niblack elf PE9KM), Vincennes, Ind. John Beaver. Sr. (WPEQAE), Pueblo, Colo. Ervin Ramos -Moll (KP4PE20), San Antonio,

Puerto Ricci Jack Perolo (P1'2PEIC). Milwaukee, Wis. Daniel Thomas (VE3PE2IR), Burlington, Ont.,

Canada Leo Alster, Rahway, N.J. C. F. Chicarelli. Bangkok, Thailand K. F. Frost, Darwin, N. T.. Australia Richard Fye, Jr., Salix, Pa. t tavid Gross, Syosset, N. Y. Bob hill, Washington, D. C. Mike Macken, Winthrop, Mass. Bill McDaniel, Markham, Ill. Canadian Broadcasting Corp., Montreal, Que., Canada Surd en Calling DX'ers Bulletin, Stockholm, Sweden

at 1100 -1110 daily, then local news to 1115 s /off. on 9750 kHz. Station returned to air at 1140 for a 17- minute xmsn in Eng. on the same channel. Re- ports go to Department of Radio, P. O. Box 1047, Kuala Lumpur, Federation of Malaysia.

Mauritius -R. Mauritius, Forest Side. now operates, as per the latest schedule, at 0230 -1300 on 9710 kHz and at 1300 -1830 on 4850 kHz, both with 10 kW.

Morocco -A qui Rabat, R. Diffusion TV Maso qui, Rabat. opens on 15,390 kHz at 2230 with a piano selection, then a newscast. followed by pop records; all- Spanish. S /off is at 0000. Do not confuse this station with Rome, which opens shortly after- ward on 15,385 kHz and runs far beyond 0000.

New Caledonia- Noumea is readable on 3335 kHz with a dramatic program at 1028 in French, semi- classical piano instrumentals at 1040, news sum- mary at 1055, and s /off with "La Marseillaise" at 1058.

Norway -The new schedule from Oslo reads: to Western N.A. and the Middle East at 0400 -0430 on 9550, 9610, and 11,850 kHz; to Pacific areas and E. Africa at 0745 -0815, to Pacific areas, Africa, Europe and S. America at 1100 -1230, to Middle East, S. Asia. Eastern N.A. and S. America at 1300 -1430, to Europe and N.A. at 1500 -1630, to Scan- dinavia, Pacific areas and Africa at 1700 -1830 and to Europe and Africa at 1900 -2030, all on 15,175, 17,825, and 21,670 kHz (also on 11,850 kHz at 0745 and 1900, 7240 kHz at 1100, and 21,730 kHz at 1300, 1500, and 1700) ; to N. Africa, Newfoundland, and S. America at 2100 -2230 on 11,850, 15.175, and 17,825 kHz; to W. and S. Africa, Newfoundland, and

December, 1966

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DX STATES AWARDS PRESENTED To be eligible for one of the DX States Awards designed for WPE Monitor Certificate holders, you must have verified stations (any frequency or service) in 20, 30, 40, or 50 different states in the U. S. The following DX'ers have qualified for and received awards in the categories indicated.

FIFTY STATES VERIFIED Richard Markel) (WPE6DXC), Los Angeles, Calif. Reg Firth (WPE2GF0), Amsterdam, N. Y. Allen Holmes (WPE7CLB), Alderwood Manor,

Wash. Dick Schier (WPE4H10), Chattanooga, Tenn. Doyle Simons (WPE4AGI), Taylors, S. C. Frank Scolaro, Jr. (WPE2LUZ), Yonkers, N. Y. Carl Durnavich (WPE9IF0), Riverdale, Ill.

FORTY STATES VERIFIED Robert Crowell (WPE4HKO), Fort Walton Beach,

Fla. Paul Ochenkowski (WPEIFYY), Hamden, Conn. Larry Zigrang (WPE9HLM), South Bend, Ind. Douglas Messimer (WPE3FMZ), Enola, Pa. Larry Himsel (WPE2NRR), North Bergen, N. J. Bruce Reynolds (WPEOEKU), Warrensburg, Mo. Joseph Aman (WPE4IFM), Clifton Forge, Va. Dave Oester (WPE7CEZ), Deer Island, Oregon

THIRTY STATES VERIFIED Brent Holcomb (WPE4HLH), Clinton, S. C. Dwain Davis (WPE1GJO), Cranston, R. I. Easy Barber (WPE5DTS), Fort Smith, Ark. Elliot Straus (WPE2NO0), West Orange, N. J. Jan Lichtig (WPE6EE0), Livermore, Calif. Norris Alford (WPE8FYF), Winfield, W. Va. Paul Pruitt (WPE6GJR), Dana Point, Calif. Barry Premeaux (WPE8HIP), Lansing, Mich. Leo Baca (WPE5CLR), East Bernard, Texas John Sgrulletta (WPE2MXF), Bedford Hills, N. Y. David Bartlett (WPE1GQK), East Hartford, Conn. Russell Feran (WPE5CXT), New Orleans, La. Harry Dence, Jr. (WPE4IKY), Cynthiana, Ky. Calvin Bright (WPE8ISA), Grass Lake, Mich. Donald Lee (WPE3EVB), Lebanon, Pa. Richard Cooper (WPE1GHI), Wayland, Mass. W. E. Raczko (WPE8JBT), Toledo, Ohio Kelly Andrews (WPE4IGA), Goldsboro, N. C. Philip Smith (WPE8IIA), Kettering, Ohio Jack Palladay, Jr. (WPE9EOE), Maxwell Air Force

Base, Ala. Alan Rhodes (WPE2000), Mountainside, N. J.

TWENTY STATES VERIFIED David Crowe (WPE3FRC), Pittsburgh, Pa. Richard Sears (WPE1FNM), Cambridge, Mass. John Megas (WPEIGJL), Ellsworth, Maine Frank Hames (WPE3CDM), Silver Spring, Md. Robert Mayer (WPE9HQG), Winnetka, III. Romona Hagerman (WPE2OBV), Delaware, N. J. Mark Hosmer (WPE9HPM), Carmel, Ind. Jerry Headen (WPE4HQL), Winston -Salem, N. C. Jimmy Chocklett (WPE4IDH), Wilson, N. C. John Tuomi (WPE2NNO), Brooklyn, N. Y. Alan Petersen (WPEOEHF), Hampton, Iowa Charles Angell (WPE3TP), Collegeville, Pa. Robert Mayer (WPE9HQG), Winnetka, Ill. Ronald Stoltz (WPE3GCE), Trafford, Pa. Robert Ruggley (WPE9HJH), Chicago, Ill. Forrest Hudspeth (WPE3FWN), Glen Burnie, Md. Gary Schwartz (WPE6GGG), Rossmoor, Calif. Gary Herron (WPE8IQN), Fraser, Mich. Robert Mansbach (WPE2NJB), Long Beach, N. Y. Roger Taylor (WPEOEMD), Independence, Mo. Ben Hughes (WPEOEMX), Seward, Nebr.

E. Kent (VE3PE2GF), Rexdale, Ontario, Canada Harold Allen (VE2PE1JM), Arvida, Quebec, Canada William Chrysler (VE6PE6K), Edmonton, Alberta,

Canada David Miller (WPE3GMH), Pittsburgh, Pa. Leroy Ireland (WPE2MSY), Ventnor City, N. J. Roger Greene (WPE2NFC), Bronx, N. Y. Paul Emch (WPE6GBG), Trabuco Canyon, Calif. David Labor (WPESEIQ), Corpus Christi, Texas Thomas Woods (WPE3GTZ), Newark, Del. Edward Greb -Lasky (WPE1GPQ), New Britain,

Conn. James Saribalis (WPE6GIB), Daly City, Calif. Richard Goldfinger (WPE200W), Pound Ridge,

N. Y. Dave Ciotti (WPE4IZC), Fairfax, Va. Marion Lilienthal (VE3PE2D0), Waterloo, Iowa Alan Rhodes (WPE2000), Mountainside, N. J. Austin Arnold (WPE1GAK), Litchfield, Conn. James Reda (WPE3FXA), Beaver, Pa. Geoff Fleck (WPE20QB), Mt. Kisco, N. Y. Thomas Break (WPE20QH), Fairlawn, N. J. Charles Schroeder (WPE8IYP), Dayton, Ohio Fred King (WPE9IEA), Wabash, Ind. Jimmy Eppright (WPE5ELM), Dallas, Texas Kenneth Kuberacki (WPERCM), Detroit, Mich. Robert Thacker (WPE8ISX), Dayton, Ohio William Vines (WPE9HVF), Hollywood, Ill. Mike Jeffrey (WPE7CLK), Wenatchee, Wash. W. F. Gilly (WPE3GNT), Allentown, Pa. Albert Earnhardt (WPE4IJN), Charlotte, N. C. Frank Colin (WPE2OPG), Suffern, N. Y. Frank Eitler (WPEIGSE), Hamden, Conn. Bruce Kesselman (WPE20GO), Woodbridge, N. J. Ron Hopkins (VE7PE7P), Trail, British Columbia,

Canada Drew Kalman (WPE8ILL), Dearborn, Mich. Kenneth Hanna (WPE3GSY), Pittsburgh, Pa. Jerome Wolf (WPE2NOQ), Rochester, N. Y. J. R. Miller (WPE7CIA), Tigard, Oregon Greg Shepard (WPE1GHL), Longmeadow, Mass. Arthur Del Gaudio, Jr. (WPE2NRT), Smithtown,

N. Y. James Brady, Jr. (WPE9HXW), Wheaton, Ill. Ronald Hartwig (WPE5ELA), Midland, Texas Michael Cohen (WPE2NTW), Brooklyn, N. Y. Samuel Gold (WPE6DXA), San Francisco, Calif. Rodney Vlach (WPEOEPG), Benson, Minn. Charles Rittenhouse (WPE8IMT), Westerville, Ohio Donny Perro (WPE4HDU), Mobile, Ala. Jonathan Lisenco (WPE2MAC), Flushing, N. Y. Leo Blouin (VE2PE1KJ), Quebec, Quebec, Canada Steve Jones (WPE410W), Lawrenceburg, Ky. Lawrence McManus (WPE2NAR), Spring Grove,

Pa. Ron Sibbett (VE3PE2HB), Cooksville, Ontario,

Canada H. K. Ogan (WPE7CIS), Mountain Home Air Force

Base, Idaho Frank Johnson (WPE2NAX), Union, N. J. Robert Braunwart (WPE7CJQ), Moses Lake, Wash. Helmut Meier (VE2PE1JZ), Sept- Illes, Quebec,

Canada Gregory Hendrix (WPE5EKJ), Galveston, Texas Ernest Doane (WPE1DTE), Lynn, Mass. Bradley Weekley (WPE8GPY), Wilbur, W. Va. James Mason (VE3PE2FB), Hamilton, Ontario,

Canada Robert Blazeyewski (WPE2FZY), South Farming-

dale, N. Y. Norm Shacat (WPE1GTP), Malden, Mass.




S. America at 2300 -0030 on 9550, 9610. and 11,850 kHz. A 30- minute program in Eng. is broadcast on Sundays at 1200, 1400, 1600. 1800, and 2000, and on Mondays at 0000 and 0400.

Peru- Station OBZ4M, R. La Voz del Valle, 3387 kHz, was heard at 0300 with Western music. Re- ports have been returned by the Peruvian post office with the notation that they cannot locate the station at Junin 834, Chaucha. Anyone have any better address for this station?

Rwanda -The Deutsche Welle relay station in Kigali was noted well on 15.435 kHz at 0020 -0035 with music and anmts in German.

Saudi Arabia -The Voice of Islam has been heard on 15,150 kHz at 1430 -1600 and on 9720 kHz at 0315- 0445, both in Arabic. They reportedly s /on at sunset in their country. (Do not confuse the 15.150 - kHz xmsn with the BBC Arabic Service on 15,140 kHz.) Their QSL arrived by registered airmail after 15 months. No schedule was received but the available channels listed were: Jeddah domestic short -wave on 7230, 9670, 11,855, and 15,150 kHz; Jeddah overseas service on 15,115 kHz; and Riyadh short -wave on 6000, 7220, 9720, and 11,950 kHz.

Singapore -R. Singapura, 7250 kHz, was noted from 1015 with teen music and anmts in Malay; at 1030 with Arabic vocal and instrumental music. News scheduled at 1045 was not presented as Arabic ran until 1100. The IS is the playing of the musical notes C, G, and E on chimes. The dual 6155 -kHz channel was barely readable.

South Africa -R. RSA, Johannesburg, was heard beamed to Canada from 2330 s /on after bird chirp and musical selection on 11,925 kHz (fair) and on 9525 kHz (covered by Havana). Another outlet, on 11,785 kHz, was noted at 2210 with Eng. news. The United Kingdom and European Service beam on 9720 kHz can be heard at 2200 -2255, dual to 7270 and 11.785 kHz.

Sweden- Recent changes: to Eastern N. A. in Eng. at 1400 -1430 and 1445 -1515, and in Swedish at

DX AWARDS PROGRAM RULES Here's an easy way to get a copy of the rules and regulations for each of the three phases of the DX Awards Program to date (Countries, States, and Provinces). Just supply a postage stamp or return envelope, and your Short-Wave Editor will send you a leaflet containing the rules for all three phases -plus a copy of the official Countries List for DX Awards. The stamp or envelope, with your request, should go to: DX AWARD RULES, P. 0. Box 333, Cherry Hill, N. J. 08034.

1515 -1600 on 17,845 kHz (replacing 15.420 kHz). Swedish at 0100 -0145 and Eng. at 0145 -0215 on 11,805 kHz (replacing 11,880 kHz) ; to Canada in French at 1615 -1645 on 17,845 kHz (replacing 15,420 kHz) ; and to Mexico and Central America in Spanish at 0400- 0430 on 11,880 and 11,705 kHz (replacing 15,420 kHz) .

Uruguay- Station CXA7, R. Oriental, 11.735 kHz. was noted at 0225 -0300 with vocal music and many organ selections. Station CXA6, S.O.D.R.E., 9620 kHz, is again being heard from 0100 to 0300 s /off with organ music and a symphony. Both stations are in Montevideo.

Vatican City -R. Vaticano, 11.760 kHz, has been heard broadcasting in Spanish to South America at 2330 -2345 and to Latin America at 0000 -0015.

V la -A new station is Ondas Panameri- canas, El Vigia. 3215 kHz, noted at 0050 -0130. An- other station, on 9747 kHz, is being heard around 1100; overseas listeners list it as R. Tocar. The latter bears further checking.

Vietnam (North) -Hanoi has moved from 9775 to 9763 kHz with Eng. at 1000.

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CIRCLE NO. 38 ON READER SERVICE PAGE December, 1966



INDEX TO VOLUME 25

JULY -DEC. 1966

AMATEUR RADIO Amateur Equipment Jamboree: 1966 (Brier) 67 Aug. Amateur Equipment Sampler 72 Aug. Amateur Radio (Brier)

Installing Amateur Antennas in Restricted Spaces 85 July

Certificate Chasing 79 Sept. Thumbnail Review of "Duo- Bander 84"

SSB Transceiver 91 Oct. New Novice Examination Questions 87 Nov. Getting the Most From Your Dipole or

Beam Antenna 77 Dec. Antenna Coupler, Technician Band (Leftwich) 87 Aug. Antenna Placement Does Make a Difference

( Ruyle) 64 Nov. Converter, GC -2 Deluxe (Smith) 41 Nov. Dit Makers (Lincoln) 64 Aug. 80/40 Meter Bandswitching Vertical (Dezettel) 73 Oct. Ham Hobby Clearinghouse 90 July Key and Bug, How to Get the Most Out of Your

(Lincoln) 68 July Modbox (Whalen) 41 Aug. Q5'er Hookup, Sure -Shot (Thompson) 87 July "Scrounge," Instant "1" Antenna (Von Trott) 46 Dec. TV Balun Useful on 6 and 2 (Youngberg) 88 Aug.

AUTOMOTIVE ELECTRONICS

Automobile Stereo Tape Players, How To Install (Davidson) 66 Nov.

"Compac" Solid -State C -D Ignition System

(Gellman) 53 Nov.

CITIZENS BAND RADIO

Antenna Placement Does Make a Difference ( Ruyle) 64 Nov.

CB Equipment, Annual Report on 51 Aug. CB'ers are Wondering About- (KOD3631) 47 Aug. Modbox (Whalen) 41 Aug. On the Citizens Band (Spinello)

Two -Way Wrist Radio and Carmunications 79 July Canadian CB'er Takes a Stand 85 Sept. The CB Image 93 Oct. DAIR Road /Vehicle System 89 Nov. CB HELP Plan Tested 79 Dec.

CONSTRUCTION

Antenna Coupler, Technician Bond (Leftwich) 87 Aug. Aquarium Heater, Static -Free Thermistorized

(Donkin) 73 Sept. Out of Tune 88 Dec.

Audio Generator, "Square Deal" (Lancaster) 59 Nov. BC -454 Goes Maritime (Marriner) 92 July Binary Counter, Integrated Circuit (Lancaster) 57 Dec. Color Organ, Musette (Lancaster) 56 July

Out of Tune 12 Sept.

112

"Compac" Solid -State C -D Ignition System (Gellman) 53 Nov.

Converter, GC -2 Deluxe (Smith) 41 Nov. Dice Game, Electric (Greenberg) 78 July 80/40 Meter Bandswitching Vertical (Dezettel) 73 Oct. Electric Shaver, Stick -Shift (Wilson) 90 Oct. Emitter Dipper (Tellefsen) 47 Dec. Extension Speakers Are No Problem (Harlow) 72 July Four on the Floor (Weems) 74 Nov.

Out of Tune 88 Dec. Hi -Fi Amplifier for Solid -State Phono Cartridge

(Trauffer) 65 Oct. Hip Squawk Box (Vlahos & Wels) 97 Oct. "Impossible" Circuit (Vicens) 72 Oct. Integrated Circuit Amplifier for Under $6

(Lancaster) 57 Oct. Intrusion Alarm, $2 (Winklepleck) 50 July Lighthouse For Short People, (Bik) 77 Nov. Little Honker (Greenlee) 55 Sept. Logic Demon (Lancaster) 41 Dec. Modbox (Whalen) 41 Aug. Phase Inverter, Long -Tailed (Weems) 69 Sept. Plasmonics For The Birds? (Drummond) 63 July Power Supply, Voltage -Regulated Battery (Sliver) 85 Nov. Q5'er Hookup, Sure -Shot (Thompson) 87 July Record Player, Solid -State Stereo (Rohen) 51 July Reflexometer Reflections 82 Oct. "Relaxatrol" to Automate Slide Projector (Towner) 55 Dec. "Scrounge," Instant "1" Antenna (Von Trott) 46 Dec. Short -Wave Receiver, Powerhouse 2 -Tube (Green) 59 Aug.

Out of Tune 88 Dec. Solderless Breadboard (Mangieri) 54 Dec. Swimming Pool Splash Alarm (Maynard) 48 July Tape Recorder Echo Chamber for Under $10

(Auyer) 81 Aug. Tesla's Thermomagnetic Motor (Cookfair) 70 Dec. Time -Signal -ONLY Receiver (Caringella) 41 Oct. TV Balun Useful on 6 and 2 (Youngberg) 88 Aug. Two -Wire Three -Way Switching Circuit

(Hitchcock & Weber) 88 July Update to Solid State (Garner) 41 Sept.

Out of Tune 88 Dec.

FEATURE ARTICLES

All on Quarter -Inch Mylar (Johns) 62 Dec. Amateur Equipment Jamboree: 1966 (Brier) 67 Aug. Antenna Placement Does Make a Difference

(Ruyle) 64 Nov. Automobile Stereo Tape Players, Install (Davidson) 66 Nov. Capacitor Know -How (Cunningham) 41 July Careers in Electronics (Gilmore) 47 Oct. CB Equipment, Annual Report on 51 Aug. CB'ers are Wondering About- (KOD3631) 47 Aug. Colorful History of Color TV (Costigan) 45 Sept. Connubially -Oriented Computer of Otto Tronix

(Kohler) 53 July CRT Slaves (Johns) 54 Sept. Di- Di- Di- Di- Di- Di- Di- Di -Dit (Kohler) 79 Nov. Dit Makers (Lincoln) 64 Aug. From Out of the Past (Hannah) 68 Oct. German TV Pioneer (Kutschbach) 72 July Handful of Power (Long) 53 Sept. "Hello, Computer? I Have Homework for 46 Aug.

Us To Do" In the Days of Spark -A Rescue at Sea (Church) 57 Nov. Infringers Beware (Kirby) 75 July Integrated Circuits! What Are They? (Lancaster) 52 Oct. Key and Bug, How to Get the Most of Your

(Lincoln) 68 July Parlor Game (Harlow) 65 Dec.

POPULAR ELECTRONICS



Quizzes (Bolin) TV Trouble 77 July Diagram 80 Aug. Cutoff /Saturation 59 Sept. Voltage Divider 64 Oct. Electronic Factor 88 Nov. Bridge Circuit 73 Dec.

St. Petersburg Tapers Go Back to School (Nelligan) 50 Dec. Science Comes to TV 66 Aug. Speakers ?, Why Are They Still Inventing (Fantel) 49 Nov. Tape Recorder, Conduct Interview With (Harlow) 63 Dec. Tape Recorders, Small (Howorka) 52 Dec. TV DX Trail, Riding the (Olson) 73 July U.F.O.'s or "Kugelblitz ?" 84 Sept. Unpopular Electroniks (Kohler) 80 Oct. War on Skating (Fantel) 66 Sept. What Are These Things Called Decibels? (Lincoln) 75 Oct.

Out of Tune 89 Dec. Will CATV Revolutionize Your TV Viewing Habits?

(Cantor) 48 Sept. Zero -Beating the News

66 July, 76 Aug., 64 Sept., 70 Oct., 72 Nov., 68 Dec.

HI -FI /STEREO AND AUDIO All on Quarter -Inch Mylar (Johns) 62 Dec. Automobile Stereo Tape Players, Install (Davidson) 66 Nov. Color Organ, Musette (Lancaster) 56 July Extension Speakers are No Problem (Harlow) 72 July Four on the Floor (Weems) 74 Nov. Hi -Fi Amplifier for Solid -State Phono Cartridge

(Trauffer) 65 Oct. Hip Squawk Box (Vlahos & Wels) 97 Oct. Integrated Circuit Amplifier for Under $6

(Lancaster) 57 Oct. Parlor Game (Harlow) 65 Dec. Phase Inverter, Long -Tailed (Weems) 69 Sept. Record Player, Solid -State Stereo (Rohen) 51 July St. Petersburg Tapers Go Back to School (Nelligan) 50 Dec. Speakers ?, Why Are They Still Inventing (Fantel) 49 Nov. Tape Recorder, Conduct Interview With (Harlow) 63 Dec. Tope Recorder Echo Chamber for Under $10

(Auyer) 81 Aug. Tape Recorder Kit -Deluxe (Heathkit AD -16) ..., 66 Dec. Tape Recorders, Small (Howorka) 52 Dec. Update to Solid State (Garner) 41 Sept. War on Skating (Fantel) 66 Sept.

PRODUCT REPORTS

Drake "SW -4," Here Comes the 78 Aug. "Duo- Bander 84" SSB Transceiver (WRL) 91 Oct. Elapsed Time Indicator Keeps Track of Stylus Wear

(Curtis) 84 Dec. Electronic Saxophone Debut (Selmer "Varitone ") 48 Nov. Tape Recorder Kit -Deluxe (Heathkit AD -16) 66 Dec.

SCIENCE FAIR PROJECTS

Audio Generator, "Square Deal" (Lancaster) 59 Nov. Binary Counter, Integrated Circuit (Lancaster) 57 Dec. Color Organ, Musette (Lancaster) 56 July Integrated Circuit Amplifier for Under $6

(Lancaster) 57 Oct. Lighthouse for Short People (Bib) 77 Nov. Logic Demon (Lancaster) 41 Dec. Plasmonics For the Birds? (Drummond) 63 July Reflexometer Reflections 82 Oct. Tesla's Thermomagnetic Motor (Cookfair) 70 Dec. Time -Signal -ONLY Receiver (Caringella) 41 Oct.

SHORT -WAVE LISTENING

BC -454 Goes Maritime (Marriner) 92 July Broadcasts from Africa and Middle East

(Legge & Hill) 94 Oct. Broadcasts from Central and South America

(Hill & Legge) 92 Nov. Drake SW -4, Here Comes the 78 Aug. DX Countries Awards Presented 114 Sept. DX Provinces Awards Presented 130 Oct. DX States Awards Presented 110 Dec. English- Language Broadcasts to North America

(Legge) 84 July, 84 Aug., 82 Sept., 96 Oct., 90 Nov., 80 Dec.

Foreign -Language Broadcasts to North America (Legge) 82 Dec.

Q5'er Hookup, Sure -Shot (Thompson) 87 July "Scrounge," an Instant "1" Antenna (Von Trott) 46 Dec. Short -Wave Listening (Bennett)

Notes From Your Short -Wave Editor's Desk 83 July A New Council for DX'ers 83 Aug. International DX Programs 83 Sept. IRC's Not Valid in Some Countries 95 Oct. Those Non -Verifying Point -to -Point Stations 91 Nov. Broadcasting Station News Around the World 81 Dec.

Short -Wave Receiver, Powerhouse 2 -Tube (Green) 59 Aug. TV DX Trail, Riding the (Olson) 73 July

SOLID -STATE CIRCUITS

Aquarium Heater, Static -Free (Donkin) 73 Sept. Audio Generator, "Square Deal" (Lancaster) 59 Nov. Binary Counter, Integrated Circuit (Lancaster) 57 Dec. Color Organ, Musette (Lancaster) 56 July "Compac" C -D Ignition System (Gellman) 53 Nov. Converter, GC -2 Deluxe (Smith) 41 Nov. Electric Shaver, Stick -Shift (Wilson) 90 Oct. Emitter Dipper (Tellefsen) 47 Dec. Handful of Power (Long) 53 Sept. Hi -Fi Amplifier for Phono Cartridge (Trauffer) 65 Oct. "Impossible" Circuit (Vicens) 72 Oct. Integrated Circuit Amplifier (Lancaster) 57 Oct. Integrated Circuits! What Are They? (Lancaster) 52 Oct. Lighthouse for Short People (Bik) 77 Nov. Little Honker (Greenlee) 55 Sept. Logic Demon (Lancaster) 41 Dec. Modbox (Whalen) 41 Aug. Power Supply, Voltage -Regulated Battery (Sliver) 85 Nov. Record Player, Solid -State Stereo (Rohen) 51 July Solid State (Garner)

80 July, 85 Aug., 76 Sept., 84 Oct., 82 Nov., 74 Dec. Swimming Pool Splash Alarm (Maynard) 48 July Tape Recorder Echo Chamber (Auyer) 81 Aug. Time -Signal -ONLY Receiver (Caringella) 41 Oct. Two -Wire Three -Way Switching Circuit

(Hitchcock & Weber) 88 July Update to Solid State (Garner) 41 Sept.

TELEVISION

Colorful History of Color TV (Costigan) 45 Sept. CRT Slaves (Johns) 54 Sept. German TV Pioneer (Kutschbach) 72 July TV DX Trail, Riding the (Gary Olson) 73 July Will CATV Revolutionize Viewing Habits? (Cantor) 48 Sept.

TEST EQUIPMENT

Audio Generator, "Square Deal" (Lancaster) 59 Nov. Modbox (Whalen) 41 Aug. Emitter Dipper (Tellefsen) 47 Dec.

December, 1966 113



Fill in coupon for a FREE One Year Subscrip- tion to OLSON ELECTRONICS' Fantastic Value Packed Catalog- Unheard of LOW, LOW PRICES on Brand Name Speakers, Changers, Tubes, Tools, Stereo Amps, Tuners, CB, and other Val- ues. Credit plan available.

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THERMOMAGNETIC MOTOR (Continued from page 71)

WEAK SPRING

6OZ. ALNICO

MAGNET

ADJUSTABLE STOP

"CANADIAN" NICKEL

'JET KING" BLOW TORCH

1/2" PIPE FLANGE

You can build motor frame with Reynolds stock aluminum, wood board, and pipe flange in half an hour.

alnico magnet, purchased at the local hardware store for $1.25, served the purpose admirably.

Almost any magnetic material can be used for the magnetic rider. Iron is an obvious choice because of its availability (nails, paper clips, and a host of other common items) . However, nickel is better since it has a much lower Curie temperature. But don't bother trying to use United States nickels -they are made of a non -magnetic nickel- copper alloy. However, Canadian nickels are quite magnetic and will work very well.

A limitless number of variations of the basic thermomagnetic motor can be devised. A few of Nikola Tesla's variations can be seen in his patent drawings. Tesla was granted two patents (numbers 396,121 and 428,057) for his invention of the thermomagnetic motor, copies of which can be obtained for 50 cents each from the Commissioner of Patents, Washington, D.C.

POPULAR ELECTRONICS



ELECTRONICS MARKET PLACE COMMERCIAL RATE: For firms or individuals offering commercial products or services. $1.00 per word (including name and address). Minimum order $10.00. Payment must accompany copy except when ads are placed by accredited advertising agencies. Frequency discount: 5% for 6 months; 10% for 12 months paid in advance. READER RATE: For individuals with a personal item to buy or sell. 60c per word (including name and address). No Minimum! Payment must accompany copy.

GENERAL INFORMATION: First word in all ads set in bold caps at no extra charge. Additional words may be set in bold caps at 10g extra per word. All copy subject to publisher's approval. Closing Date: 1st of the 2nd preceding month (for example, March issue closes Janu- ary 1st). Send order and remittance to: Hal Cymes, POPULAR ELECTRONICS, One Park Avenue, New York, New York 10016.

FOR SALE

FREE! Giant bargain catalog on transistors, diodes, rectifiers, SCR's, zeners, parts. Poly Paks, P.O. Box 942, Lynnfield, Mass. MESHNA'S TRANSISTORIZED CONVERTER KIT $5.00. Two models converts car radio to receive 30 -50 mc or 100 -200 mc (one mc tuning). Meshna, North Reading, Mass. 01864. GOVERNMENT Surplus Receivers, Transmitters, Snooper - scopes, Radios, Parts, Picture Catalog 25g. Meshna, Nahant, Mass. 09108. CANADIANS -GIANT Surplus Bargain Packed Catalogs. Electronics, Hi -Fi, Shortwave, Amateur, Citizens Radio. Rush $1.00 (Refunded). ETCO, Dept. Z., Box 741, Mon- treal, CANADA. WEBBER LAB'S Police -Fire Transistorized Converter kit 30 -50mc, & 100-200mc. (1 mc. spread) $5.00 each. 26- 200mc. on broadcast band using any type radio, crystal controlled $23.00 wired pp. tunable -crystal controlled $11.00 kit. 72 Cottage Street, Lynn, Mass. JAPAN & Hong Kong Electronics Directory. Products, components, supplies. 50 firms -just $1.00. Ippano Kaisha Ltd., Box 6266, Spokane, Washington 99207. CANADIANS, TRANSISTORS AND PARTS. Free catalogue contains reference data on 300 transistors. J. & J. Elec- tronics, Dept. PE, Box 1437, Winnipeg, Manitoba. CANADIANS -Free catalogue radio TV parts, electronics. Gladstone Electronics, 1923 Avenue Rd., Toronto, Canada. TRANSISTORS -Miniature Electronic Parts. Send for free Catalog. Electronic Control Design Company, P. O. Box 1432K, Plainfield, N.J.

INVESTIGATORS, FREE BROCHURE, LATEST SUBMINIA- TURE ELECTRONIC SURVEILLANCE EQUIPMENT, ACE ELECTRONICS, 11500 -L NW 7TH AVE., MIAMI, FLA. 33168.

SEE YOURSELF ON TV! Closed- circuit TV CAMERA KITS for experimenters, industry, schools. Wide selection of tube and transistor models, $18.95 up. EASY -TO- FOLLOW PLANS included FREE with each kit or available sepa- rately ($3 to $5)- refundable with later order. CHECK OUR UNBELIEVABLE PRICES. Informative catalog 100. ATV RESEARCH, Box 396P, So. Sioux City, Neb. 68776.

CB -WPE -QSL CARDS. Same High Quality, Beautiful, Glossy multi -color cards. New LOW PRICES. 26 SAM- PLES, 25¢. Dick, W8VXK, 19QA0625, Gladwin, Mich. 48624.

R.F. CONVERTERS. World's largest selection. Also CCTV cameras, transmitters, etc. Lowest factory prices. Cata- log 100. Vanguard 196 -23 Jamaica Ave., Hollis, N.Y. 11423.

GIANT TESLA COIL- FORTY -INCH SPARKS! Complete plans $5.00. Details, color photo 50g (deductible). Huntington Electronics, Inc., Box 9 Huntington Station, Shelton, Conn. 06484. TELEPHONE VOICE SWITCH: (LS -500). ACTUATES AUTO- MATICALLY AND UNATTENDED ANY TAPE OR WIRE RE- CORDER. PICTORIAL INSTALLATION INSTRUCTIONS INCLUDED. $23.75. POST PAID USA, WJS ELECTRONICS. 737 NORTH SEWARD, HOLLYWOOD, CALIF. 90038.

December, 1966

ELECTRONIC "CRACKAJACKS," relays, transistors, photocells, etc. Guaranteed prizes. $1.00 ppd. DART ELEC- TRONICS, Box 214, Jericho, N.Y. ORIENTAL Electronics Directory, 200 Japanese -Hong Kong Manufacturing Exporters. All products. $2. Dee, Box 211, Beverly Hills, Calif. 90213. INVESTIGATORS: KEEP IN STEP WITH ADVANCEMENTS IN THE ART OF ELECTRONICS FOR THE PROFESSIONAL. SEND $1.00 FOR EQUIPMENT BROCHURE. WJS ELEC- TRONICS, 737 NORTH SEWARD, HOLLYWOOD, CALIF. 90038. BUG DETECTOR: WILL DETECT AND LOCATE SURREPTI- TIOUS TRANSMITTING DEVICES IN CONFERENCE ROOMS, HOME AND OFFICES, ETC. WRITE FOR DETAILS. WJS ELECTRONICS, 737 NORTH SEWARD, HOLLY- WOOD, CALIF. 90038. RECTIFIERS, transistors, other components. Catalog free. Electronic Components Co., Box 2902C, Baton Rouge, La. TRANSISTORIZED Products Importers catalog. $1.00. Intercontinental, CPO 1717, Tokyo, Japan. RADIO - T.V. Tubes -33g each. Send for free catalog. Cornell. 4213 University, San Diego, Calif. 92105. CIRCUIT Boards, Parts for "Poptronics" projects. Free catalog. DEMCO, Box 16297, San Antonio, Texas 78216. ROCKETS: Ideal for miniature transmitter tests. New illustrated catalog, 250. Single and multistage kits, cones, engines, launchers, trackers, rocket aerial cameras, technical information. Fast service. Estes Industries, Penrose 18, Colorado. COMPONENTS? Kits? Hardware? For catalogue write Trans -Vu -Pacs, Box 267, Chelsea, Mass. 02150. LOWEST Prices Electronic Parts. Confidential Catalog Free. KNAPP, 3174 8th Ave. S.W., Largo, Fla. SURVEILLANCE EQUIPMENT -NEW HIGH PERFORM- ANCE SUBMINIATURE MODELS. ELECTRONIC COUN. TERMEASURE DEVICES TO PROTECT PRIVACY. FREE DATA: SECURITY ELECTRONICS -PE, 15 EAST 43RD STREET, NEW YORK, N.Y. 10017.

SURPRISE electronics equipment $5.00, $10.00 package. Tang, Box 162, Framingham Center, Mass. 01701.

CB -QSL CARDS, New Designs, Record Books, Blabber- mouth Awards, Gag Signs, Warning Decals, Novelties. Free Brochure. WOODY, 8474 Watson, St. Louis, Mo. 63119.

CRYSTALS ... largest selection in United States at lowest prices. 48 hr. delivery. Thousands of frequencies in stock. Types include HC6 /U, HC18 /U, FT -241, FT -243, FT -171, etc. Send 10¢ for catalog with oscillator circuits. Re- funded on first order. Jan Crystals, 2400F Crystal Dr., Fort Myers, Fla. 33901.

McGEE RADIO COMPANY. Big 1966 -1967 catalog sent free. America's best values. HiFi Amplifiers- speakers- electronic parts. Send name, address and zip code number to McGee Radio Company, 1901 McGee Street, Dept. EG, Kansas City, Missouri 64108.

SAFEGUARD YOUR PRIVACY. Learn the facts, procedures and techniques in the art of de- bugging your home, office, boardroom or auto. $7.95. Tron -X, Post Office Box 38155, Hollywood, Calif. 90038.

115



HIFI speaker system. Small, walnut. Magnificent. $29.95. TANG, Box 162A, Framingham Ctr., Mass. 01701. HOBBYISTS, EXPERIMENTERS, AMATEUR SCIENTISTS, STUDENTS . CONSTRUCTION PLANS -All complete including drawings, schematics, parts lists, prices, parts sources ... LASER -Build your own coherent -light optical laser. Operates in the pulsed mode, in the visible light range -$6.00. . . DIODE LASER- Invisible light (infra- red) can be continuously modulated -$3.00 . RE- VERBERATOR (ECHO) UNIT -Build your own. Use with your automobile radio, home radio or hifi, electric guitar, etc. -$3.00 . RADAR -Build your own ultrasonic doppler radar. Detect motion of people, automobiles, even falling rain drops. Transistorized. uses standard small 9 -volt battery -$4.00 . . TV CAMERA -Build your own. The real thing -no rotating disc. Uses 5 tubes plus videcon tube. Output: 72 ohms or receive on any TV set channel 2 -6. Excellent circuit -good picture -$6.00

. STROBOSCOPE -Flash rate variable from about 10 to 1,000 flashes per second. Stop effect will allow you to view rotating or oscillating objects while in motion -$3.00. . STEREO AMPLIFIER -Uses two 6T9 com- pactrons -for stereo phono, tuner, etc. -$3.00. . TWO - WAY TALK OVER FLASHLIGHT BEAMS -Hand -held microphone, loudspeaker volume. Use in daylight or darkness -$3.00 ... VIBRATO UNIT -Use with electric guitar and other musical instrument amplifiers. Uses two transistors and two 9V batteries -$3.00 . . . VOLUME COM- PRESSOR /EXPANDER -Use with your HiFi -$4.00 .

LONG-RANGE "SOUND TELESCOPE" -This amazing device can enable you to hear conversations, birds and animals, other sounds hundreds of feet away. Very directional. Transistorized. Uses 9V battery -$3.00 . .

CIGAR BOX ELECTRIC ORGAN -Portable, self- contained battery. Eight notes, one octave. Two transistors, 9V battery -$3.00 ... ANALOG COMPUTER -Multiply, divide, add, subtract, square and find square roots. Uses two flashlight batteries -$3.00. . . BINARY READOUT -Pro- gram in decimal numbers and readout binary -$3.00

. SOLID STATE BINARY COUNTER (COMPUTER - ADDER) -Uses transistor flip -flop stages. Lightbulb readout. Punch in pulses, read binary count. Five stage. In- cludes easy to understand discussion of decimal to binary arithmetic conversion. Excellent start in digital computer technology -$6.00 . . TECHNICAL WRITERS GROUP, Box 5501, STATE COLLEGE STATION, RALEIGH, N.C. 27607.

DIAGRAMS for repairing Radios $1.00. Television $2.50. Give make model. Diagram Service, Box 1151 PE, Man- chester, Connecticut 06042. EXPERIMENTER'S GIANT Catalog 250 exclusive items - 25f, refundable. Laboratories, 12041 -L Sheridan, Garden Grove, Calif. 92640. WORLD'S Tiniest Radios. Recorders, Transceivers, Port- ables. Free Catalog. Minitronics, 1983 -1065 Via Del Rio, Corona. California 91720. PRINTED CIRCUIT BOARDS, made to specifications. Free catalogue. C &S, 366 Marie Ct., East Meadow, N.Y. 11554.

ELECTRONIC Ignition Kits, Components, Free Diagrams. Anderson Engineering, Epsom, New Hampshire 03239. FREE catalog of transistors, diodes, parts, equipment. Surabachi Electronics, 214 E. Brett, Inglewood, California 90302. CB -QSL CARDS -Fast service- One color 1000, $10.50. Humphries, P.O. Box 574, Bacliff, Texas 77518. FREE CATALOG Transistors, Diodes, Parts. Solid State Pax, P.O. Box 206, Dorchester, Mass. 02124. SACRIFICE: Personal inventory. Test equipment, tape recorders, components. Send 25¢ for catalog. Robert Willis, Box 35305, Georgia Tech, Atlanta, Georgia 30332. NEED RESISTORS? Standard 1/2 -watt, 10% carbon 5¢ each, Postpaid. Minimum order $1.00. FREE SAMPLE and order blank. TEPCO, Box 508, Tullahoma, Tenn. 37388. ELECTRONIC SURVEILLANCE DEVICES, detectives, hobbyists. SNOOPER FM wireless microphone $44.50. TAIL - ABEEP, bumper beeper $99.50. TELEGAB phone transmitter $49.50. Other guaranteed high quality items in our catalog. Fudalla Associates, 1134 Avenue Road, Toronto 12, Ontario, Canada.

ELECTRONIC ignition Kits, Components, Free Diagrams. Anderson Engineering, Epsom, New Hampshire 03239.

ACHTUNG! Das machine is nicht fur Gerfingerpoken und mittengraben. Is easy schnappen der Springenwerk, blowenfusen und poppencorken mit spitzensparken. Ist nicht fur gerwerken by das Dummkopfen. Das rubber - necken sightseeren keepen hands in das pockets. Relaxen und watch das Blinkenlights. This attractive, brass metal plaque only $2.00 each, ppd. Southwest Agents, Dept. P, P.O. Box 12283, Fort Worth, Texas 76116.

DETECTIVES! Free Brochures! Electronic Surveillance SHORTWAVE LISTENING Devices. SILMAR ELECTRONICS, 3476 N.W. 7th Street, Miami, Fla. 33125. FREE ELECTRONICS (new and surplus) parts catalog. We repair multimeters. Bigelow Electronics, Bluffton, Ohio 45817. NEW supersensitive transistor instrument detects buried gold, silver, coins. Kits, assembled models. $19.95 up. Free catalog. Relco -A33, Box 10563, Houston 18, Texas.

CONVERT any television to sensitive, big- screen oscilloscope. Only minor changes required. No electronic experience necessary. Illustrated plans, $2.00. Relco -A33, Box 10563, Houston 18, Texas.

WE SELL CONSTRUCTION PLANS. AMAZING NEW SUPER HOBBY CATALOG 25¢. TELEPHONE: Answering Machines, Speaker Phones, Mobile Phones, Automatic Dialers, Central Dial Systems, Phonevision, Legal Con- nectors, Laser Links. TELEVISION: Cameras, 3D Con- verters, Color TV Converters, Video Recorders. HOBBY- IST: Teletypes, Electron Microscopes, Tranquilizers, Private Eye Tail Transmitter. Plans $4.95 Each. COURSES: Electronics, $22.75; Detective Electronics, $22.50; Telephone Engineering, $39.50. Don Britton Enterprises, 7906 Santa Monica Blvd., Hollywood, Calif. 90046.

POLICE -AIRCRAFT- EMERGENCY CALLS on your broadcast radio with TUNAVERTER! Economical -Practical! Tune the Band! Only $29.95! FREE catalog. Salch & Co., D,-,f. i Woodsboro. Texas 78393.

LINE TRANSFORMER 2.5KW, four isolated windings 115V -21 amps 50 /60cy 12x11x12 any combinations of 115 -230V possible, 95 lbs. $44.95, GREAT BUYS catalog 100. Fertik's, 5249 "D" St., Philadelphia, Pa. 19120.

116

SWL GUIDE, English programs listed by the hour. REVISED EDITION, $2.00. SWL Guide, 218 Gifford, Syra- cuse 2, N. Y.

HAM EQUIPMENT

CBers, HAMS, SWL's! 3 -30 MC Preselector kit, $18.98. CB booster Kits. Novice transceiver kit, $29.95. Free catalog. HOLSTROM, Box 8640 -E, Sacramento, Calif.

HIGH FIDELITY

"LOW, Low quotes: all components and recorders. HiFi, Roslyn 9, Penna."

HI -FI Components, Tape Recorders, at guaranteed "We Will Not Be Undersold" prices. 15 -day money -back guarantee. Two -year warranty. No Catalog. Quotations Free. Hi- Fidelity Center, 239 (P) East 149th Street, New York 10451.

FREE! Send for money saving stereo catalog #P12E and lowest quotations on your individual component, tape recorder, or system requirements. Electronic Values, Inc., 200 W. 20th St., New York. N.Y. 10011.

TONE -CONTROL preamplifier. Low -noise FET design. 25

db bass and treble boost. 20 db treble cut. $35. Vernon Ritter, Nittany Avenue, Boalsburg, Pennsylvania 16827.

POPULAR ELECTRONICS



TAPE AND RECORDERS

BEFORE Renting Stereo Tapes try us. Postpaid both ways -no deposit- immediate delivery. Quality -Dependability -Service -Satisfaction -prevail here. If you've been dis- satisfied in the past, your initial order will prove this is no idle boast. Free Catalog. Gold Coast Tape Library, Box 2262, Palm Village Station, Hialeah, Fla. 33012. RENT 4 -TRACK STEREO TAPES -Dependable service our keynote -ALL MAJOR LABELS -FREE CATALOG (48 States) -TRIMOR Company, P.O. Box 748, Flushing, N.Y. 11352.

STEREO TAPES. Save up to 60% (no membership fees, postpaid anywhere U.S.A.). Free 60 page catalog. We discount batteries, recorders, tape accessories. Beware of slogans not undersold," as the discount information you supply our competitor is usually reported to the factory. SAXITONE, 1776 Columbia Road, Washington, D.C.

AUTOMATIC telephone connection for Concord and other transistorized recorders. SURVEILLANCE and Privacy Protection Devices. Free Data: Security Electronics -PER, 15 East 43rd Street, New York, N.Y. 10017. TAPE transport. NAB recording studio quality. Build yourself for amazingly low cost. Detailed plans $5.00. Free particulars. Pepke Laboratories, 309 -B West 19 Street, New York, N.Y. 10011. TAPE -MATES now offers ALL TAPES -ALL LABELS at TRE- MENDOUS SAVINGS plus FREE Tape -Mates membership. For FREE brochure write TAPE -MATES, 5727 -PE W. Jeffer- son Blvd., Los Angeles 90016. TAPES. TAPE RECORDERS -sold, exchanged. Free catalog. Tower, Lafayette Hill, Pa. 19444. TAPE RECORDER SALE. Brand new, latest models, $10.00 above cost. Arkay Sales, 1028 -C Commonwealth Ave., Boston, Mass. 02215. RENT Stereo Tapes -over 2,500 different -all major labels -free brochure. Stereo -Parti, 1616 -PE Terrace Way, Santa Rosa, California. TAPE RECORDERS, Hi -Fi, components, Sleep Learning Equipment, tapes. Unusual Values Free Catalog. Dress - ner, 1523R, Jericho Turnpike, New Hyde Park, N. Y. 11040. EXCHANGE STEREO TAPES. Catalog. Art's, 4431A Avo- cado Street, Hollywood, Calif. 90027.

TUBES

BEFORE You Buy Receiving Tubes, Transistors, Diodes, Electronic Components and Accessories . send for Giant Free Zalytron Current Catalog, featuring Standard Brand Tubes: RCA, GE, etc. -all Brand new Premium Quality Individually Boxed, One Year Guarantee -all at Biggest Discounts in America! We serve professional servicemen, hobbyists, experimenters, engineers, technicians. Why Pay More? Zalytron Tube Corp., 469 -E Jericho Turnpike, Mineola, N. Y. 11502. TUBE Headquarters of World! Send 10¢ for Catalog (tubes, electronic equipment) Barry, 512 Broadway, N.Y.C. 10012. TUBES "Oldies ", latest. Lists free. Steinmetz, 7519 Maplewood, Hammond, Indiana 46324. FREE Catalog. Electronic parts, tubes. Wholesale. Thousands of items. Unbeatable prices. Arcturus Elec- tronics ZD, 502 -22 St., Union City, N.J. 07087. RADIO & T.V. Tubes -33f each. Send for free list. Cornell, 4213 University, San Diego, Calif. 92105. TOOOOBES: HIFI, Transmitting, Special Purpose. Brand NEW- Lowest Prices. CATALOG!!! Vanbar Distributors, Box 444F, Stirling, New Jersey 07980.

WANTED

CASH Paid! Unused tubes, electronic equipment. Barry, 512 Broadway, N.Y.C. 10012.

HARD -TO -GET TUBES IN STOCK Type 200 -OOA

01A 0C3-133 OD3 IA7 ...1.75 183 IHS ...1.50 3L6 .. 1LA4 1LA6 1LC5 1LC6 1L05 1LE3 1LH4 1LN5 1N2A INS 1P5

1R5 155 175 lU4 1U5 1V .

1V2 2A3 2A5 2A6 287 2HÁ5 2X2A 3A3 3Á5 3AÚ6 387 .. 36N4 3826 3066 3004 3056 3V4 4807 4BU8 4827 4066. SAME SAN8 5AQS SASH 5AT8 5AZ4 5807 5888 5CG8 SHA7 5J6 5U4 5U8 5V4 5W4 5X8 513 554 5Z3 5Z4 6A7 6A8 6A84 6AB7

BRAND Price

2.00 .2.75

.85 .75 .88

6.25 1.30 1.98 1.05 1.80 1.95 1.25

. 2.80 2.25 1.60 1.85 2.00

1.10 1.10 .80

1.05 .98 2.00 .83

3.75 2.50 4.50 1.95 1.49 1,95 .75

3.10 .82 2.39 1.08 .g3 .82

1.48 2.00 .95

1.45 1.39 1.45 .82

1.40 1.55 .82

1.64 1.44 2.00 1.35 1.50 1.19 1.20 1.05 .59

1.19 1.35 1.75 1.30 .61

1.45 1.54 3.00 3.05 2.49 .80 .96

NEW Type 6A05 6AC7 6AF3 6AG5 6AC7 6AH4 6AK5 6ÁL3 6AL7 6AM8 6AN8 6AQ7 6AR5 6AS5 6A57 6AT6 6A78 6AÚ4 6AU5 6AU6 6AÚ8 6AW8 6AX4 6AX5 6AX7 .

684 .. 687 -

BBB 6BR6 6BÁ6 68E6 66H6 68N8 6665 661(7 6806 6807 66X7 604 6C5M 6C6 6C8G 6CÁ7 6007 6008 6CL6 6CL6 6CM7 6CQ8 6C57 6CW4 60X8 6C25 604 .

606 60A4 6086 6DN7 6004 6005 6006 6E5 .

6F4 .

6F50T 6F6G 6F7 ..4.39 6F8 .

6GJ5 6095 6096 6HZ8 6350

PriCe 2.2-. 1.7, 1.05 1.03 2.2E 1.10

.80 1.0' 2.40 1.15 1.43 1.33

.88

.95 3.15 ,7-

1.25 1.28 1.60 .68

1.50 1.35 .96

1.10 1.25 5.95 2'75 2.66 .68

1.35 .81 .95

1.35 1.35 1.20 1.42 1.18 1.95 .64

1.95 2.50 2.95 2.59 .75 95 1.45

1.50 1.17 1.39 1.30 1.90 1.82 1.75 1.75 2.50 1.25 3.05 1.45 1.05 2.25 1.00 2.25 3.20 1.72 1.95 3.08 2.42 1.66 1.18 2.38 1.34

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..2.50 .93 ..1.90

.1.90 1.50 2 58 ,90

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.2.95 .2.34 ,2.52 3.00

.1.90 .2 .85

.2.14 .1.15 .1.25 .2.75 .1.28 .2.00 .1.25 .1.95 .2.84 .3.10 .2.25 .1.95 .1.25 .2.50

GUARANTEE , YYe

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.99

.99 1.398 1.59 1.59 3.59 1.30 1.14 1,76 1.56

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1.35 1.08 1.09 .95

.2.49 2.95

. 1.13 .50

.1.50 1.48 1.50 .90

1.98 1.72 1.50

.1.50 1.40 1.33 1.35 1.00

.1.33

. 1.33 1.75 2.21 1.45 1.35 1.85 1.85 1.90 1.95 1.75 2.33 1.39 1.39 3.10 2.23 1.95 1.95

Type 14N7 í4Q7 í4R7 1457 í4W7 14X7 í4Y4 19 4 22 24A 25C5 25CD6 25..N6 25L6 25Z5 LSZ6 26 L7

32 32ET5 33 33077 ;4 3SÁ5 35L6 35W4 351-4 3523 3525 36 ... 37 38 39/44 41 42 43 45/2A3 48 ... 48 ... 49 ... 50 50A1 SOCS 50L6 50X6 5O56 5057 53 .

55 .

56 57 58 59 70L7 71A 75 76 77 78 80 83 5881 6146 6336. 6330 807 91-88

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..1.15 ..1.50

.75 1.94 2.40 .80

.1.15

.1.10 ...1.60 ...1.75

.1.25 .88

1.15 3.00 1.25 2.10 1.05 .47

1.62 1.54 .82

1.50 .. 1.25 1.25 1.25

.. 1.50 1.94 2.75 3.25 .95

4.00 3.50 1.75 3.50 .85

1.10 2.10 1.55 1.48

. 3.50

. 2.75 1.45

. 1.75 175

. 3.50 2.00

. 1.25 2.60

. 1.75

. 2.00

. 1.75

. 1.75

. 1.48 3.00 2.75 4.75 4.00

.95 4.75

MINIMUM ORDER $5.00 POSTAGE EXTRA

UNITED RADIO CO. P.O. Box -1000 Al2 NEWARK, N.J.

Send fo Miete TUBE CATALOG

Tr,.i, L. A Pnrtiai List

CIRCLE NO. 42 ON READER SERVICE PAGE QUICKSILVER, Piatinum, Silver, Gold. Ores Analyzed. Free Circular. Mercury Terminal, Norwood, Mass. MILITARY SURPLUS EQUIPMENT NEEDED: ARC -34, ARC - 38, ARC -44, ARC -52, ARC -54, ARC -55, ARC -66, ARC -73, ARC -84, ALSO ARN -14C, ARN -54, ARN -59. COLLINS 51X- 2, 51V -3, 51Y -3, 51R -3, 17L -4, 17L -7, 618S -1, 18S -4. BENDIX TA -21, RA -21. APR -14, PRC -25, RT -66 THRU RT -70 /GRC. APN -22, APN -117, APN -133. TEST SETS WANT WITH ARM, UPM, URM, USM, SG PREFIXES. TOP CASH DOL- LAR PAID IMMEDIATELY. SLEP ELECTRONICS CO., DRAWER 178 -PE; ELLENTON, FLORIDA 33532, PHONE (813) 722 -1843.

EQUIPMENT

FREE electronics catalog. Tremendous bargains. Send postcard. Electrolabs, Department C -672D, Hewlett, New York 11557.

REPAIRS AND SERVICES

TV Tuners rebuilt and aligned per manufacturers specification. Only $9.50. Any make UHF or VHF. We ship COD. Ninety day written guarantee. Ship complete with tubes or write for free mailing kit and dealer brochure. JW Electronics, Box 51C, Bloomington, Indiana.

December, 1966 117



INSTRUCTION

LEARN ELECTRONIC ORGAN SERVICING at home all makes including transistors. Experimental kit- trouble- shooting. Accredited NHSC, Free Booklet. NILES BRYANT SCHOOL, 3631 Stockton. Dept. A, Sacramento 20, Calif.

LEARN While Asleep, hypnotize with your recorder, phonograph. Astonishing details, sensational catalog free! Sleep- Learning Association, Box 24 -ZD, Olympia, Wash.

BOOKS

CANADIANS -Fabulous Electronic Book Catalog- listing over 500 Titles -Free. Books, Box 796A, Montreal. FREE CATALOG. Adult Books. POSTAL PE, 2217 Lack - land, St. Louis, Missouri 63114. FREE Book. Prophet Elijah Coming Before Christ. Wonder- ful Bible Evidence. PE Megiddo Mission, Rochester, New York 14619.

FCC License in 6 weeks. First Class Radio telephone. Re- INVENTIONS WANTED sults Guaranteed. Elkins Radio School, 2603B Inwood, Dallas, Texas.

REI First Class Radio Telephone License in (5) weeks Guaranteed. Tuition $295.00. Job placement free. Radio Engineering Institute, 1336 Main Street, Sarasota, Fla.

F.C.C. LICENSE (first class) in seven weeks. Resident classes or correspondence. Grantham, 1505 N. Western, Hollywood, California 90027.

HIGHLY -effective home study review for FCC commercial phone exams. Free literature! Cook's School of Elec- tronics, P.O. Box 10634, Jackson, Miss. 39209.

"HOW TO MAKE MONEY WITH SIMPLE CARTOONS" - Everyone who likes to draw should have this book; FREE. Send name, zip code. Cartoonists' Exchange, 21312 Pleasant Hill, Ohio 45359.

FCC LICENSE THROUGH TAPE RECORDED INSTRUC- TION. Bob Johnson Audio -Visual Training, 1060D Duncan, Manhattan Beach, Calif. 90266.

BINARY ARITHMETIC booklet. Learn the arithmetic of computers. $1.00. ECR Traders P -2, Box 3064, Falls Church Va. 22043.

HIGH SCHOOL DIPLOMA at home. Qualified instructors. Send age, highest grade completed, for free details. No salesman. SOUTHERN STATES ACADEMY, Professional Bldg., Dept. 5, Decatur, Ga.

GOVERNMENT SURPLUS

"GOVERNMENT SELLS ". -Surplus Electronics; Oscillo- scopes; Transceivers; Test Equipment; Radar; Walkie- Talkies; Boats; Jeeps; Aircraft; Misc. -Send For -"U.S. Depot Directory -Procedure " -$1.00- Service, Box 425 (ZE), Nanuet, N.Y.

GOVERNMENT Surplus. Complete Sales Directory $1.00.

INVENTIONS wanted. Patented; unpatented. Global Mar- keting Service, 2420 -P 77th, Oakland 5, Calif. INVENTIONS -IDEAS developed: CASH /ROYALTY SALES. Member: United States Chamber of Commerce. Raymond Lee, 130 -G West 42nd, New York City 10036.

INVENTORS! Sell your invention for cash or royalties! Our client manufacturers eagerly seek new items. Patented. Unpatented. Financial assistance if needed. 25 years proven performance. For free information, write Dept. 20, Gilbert Adams, Invention Broker, 80 Wall St., New York 5, N.Y. INVENTORS! Don't sell your invention, patented or unpatented, until you receive our offer. Eagle Development Company, Dept. P, 79 Wall Street, N.Y. 5, N.Y.

PATENT Searches including Maximum speed. full airmail report and closest patent copies, $6.00. Quality searches expertly administered. Complete secrecy guaranteed. Free Invention Protection forms and "Patent Informa- tion." Write Dept. 9, Washington Patent Office Search Bureau, 711 14th Street, N.W., Washington 5, D.C.

INVENTORS. We will develop, help sell your idea or invention, patented or unpatented. Our national manufacturer clients are urgently seeking new items for outright cash sale or royalties. Financial assistance available. 10 years proven performance. For free information, write Dept. 41, Wall Street Invention Brokerage, 79 Wall Street, New York 5, N.Y.

INVENTORS! Outright cash sale or royalties for your inventions. Patented. Unpatented. Active demand from our client manufacturers. Financial assistance available. Write Dept. 35, United States Invention Brokerage, 78 Wall Street, New York 5, N.Y.

INVENTIONS Wanted! Patented, unpatented. Extensive manufacturers lists. Free details: write Pioneer Inven- tion Service, Dept. 79, 150 Broadway, New York, N.Y. 10038.

Surplus Publications. Box 45781E, Los Angeles 45, Calif. AUTHORS' SERVICES JEEPS Typically From $53.90 . . . Trucks From $78.40 . . . Boats, Typewriters, Airplanes, Electronics Equip- ment, Photographic Equipment, used. 100,000 Bargains Direct From Government. Complete Sales Directory and Surplus Catalog $1.00 (Deductible First $10.00 Order). Surplus Service, Box 820 -J, Holland, Mich. 49424.

REAL ESTATE

FREE Fall -Holidays CATALOG! Big 180 pages! Selected Best thruout the U.S. Thousands of properties described, pictured -Land, Farms, Homes, Businesses -Waterfront, Recreation, Retirement. 66 Years' service, 490 Offices, 36 states Coast to Coast. Mailed FREE from the World's Largest! STROUT REALTY, 60 -ZD, East 42nd St., N.Y., N.Y. 10017.

PEACEFUL SOUTHERN UTAH VALLEY, 21/2 Acres $250. Dept. ZD, Box 17401 Holladay, Utah.

CANADIAN VACATION LANDS: Full price $385.00. 40 acres, $10 month. Suitable cottage sites, hunting, fishing, investment. Free information, Land Corporation, 3768 -P,

Bathurst, Downsview, Ontario, Canada.

118

AUTHORS! Learn how to have your book published, pro- moted, distributed. FREE booklet "LO," Vantage, 120 West 31 St.. New York 1.

SONGWRITERS WANTED. Send songs for recording - royalty contract. Tin Pan Alley, 1650 -H Broadway, New York 10019.

RECORDS

REPLACE worn LP Jackets -white 200, colors 250. Min. shipment 20, samples 500. Jacket Supplies, Hillburn P.O., New York. DORIC COMBO ORGAN RECORD. Hear the swinging sounds for 25f, Doric Organs, Box 1, Convent, N.J. 07961.

MUSICAL INSTRUMENTS

ACCORDIONS, GUITARS, BAND INSTRUMENTS! Save to 50%. Terms. Trades. Free trial. Free catalog. Mention instrument. MUSIC MART, 5535 -PE Belmont, Chicago 60641.

POPULAR ELECTRONICS



MUSIC

BE MAD. Buy M.A.D.. Enjoy "music- only" programs now broadcast on FM with MA's sub carrier detector plugged or wired into your tuner. Kit $49.50. Wired $75.00. List of FM stations with SCA authorization $1. Music Associated, 65 Glenwood Road, Upper Montclair, New Jersey (201) 744 -3387.

SELF- HYPNOTAPBS. Send for FREE brochure, "WHAT'S IT ALL ABOUT?" PERSONALIZED TAPES, Box 190PE, Quincy, Massachusetts 02169.

FREE TRIAL!! Sensational self- hypnosis record kit. Forum, 333 -AA12 Michigan, Chicago 60601.

DO -IT- YOURSELF

POEMS wanted for new songs. Nashville Music Institute, SAVE! Build Transistorized Treasure Finder. Details Free. Box 532 -E, Nashville, Tennessee. Del Research, Box 436A, Centerville, Georgia 31093.

BUSINESS OPPORTUNITIES

INVESTIGATE Accidents -Earn $750 to $1,400 monthly. Men urgently needed. Car furnished. Business expenses paid. No selling. No college education necessary. Pick own job location. Investigate full time. Or earn $6.44 hour spare time. Write for Free literature. No obligation. Universal, CZ -12, 6801 Hillcrest, Dallas, Texas 75205. VENDING Machines -No Selling. Operate a route of coin machines and earn amazing profits. 32 -page catalog free. Parkway Machine Corporation, 715PE Ensor Street, Baltimore 2, Md.

ELECTROPLATING Equipment and supplies. All types for home workshops and industrial. Send $1.00 (refundable) for equipment guide formulas, operating data, catalog. HBS Equipment Division 90, 3543 East 16th, Los An- geles, California. 90023.

PIANO Tuning learned quickly at home. Tremendous field! Musical knowledge unnecessary. Information free. Empire School of Piano Tuning. Dept. PE. Box 327, Shen- andoah Station, Miami, Florida 33145. (Founded 1935.)

CITIZENS BAND Radio Dealerships Available. Sell Full or Part Time. Knox Electronics, Dept. 274, Galesburg, Ill. 61401.

RAISE RABBITS for us on $500 month plan. Free details. White's Rabbitry, Mt. Vernon 52, Ohio. FREE CATALOGS. Repair air conditioning, refrigeration. Tools, supplies, full instructions. Doolco, 2016 Canton, Dallas, Texas 75201.

I MADE $40,000.00 Year by Mailorder! Helped others make money! Start with $10.00 -Free Proof. Torrey, Box 318 -N, Ypsilanti, Michigan 48197.

FREE Book "990 Successful, little -known Businesses." Work home. Plymouth -945P, Brooklyn, N.Y. 11218.

HOW TO GET FINANCIAL CAPITAL, Loans, Grants, Cash to Start a Business. Free details. Counselor -47, Har- lingen, Texas 78551.

FREE book: "America's Best Home Opportunities ". Kinder, 615 -77th Avenue, Laval, Quebec, Canada.

HYPNOTISM

HYPNOTIZE UNNOTICED! PATENTED new hand device makes you a Hypnotist first day or refund! Hypnotist's Handbook included! $2.00 Hypnosis Foundation, Box 487, La Mesa 9, California.

FREE Hypnotism, Self- Hypnosis, Sleep Learning Cata- log! Drawer H400, Ruidoso, New Mexico 88345.

PLANS AND KITS

ALLWAVE RADIO KIT. Tube, transistor included $5.00. Headset $2.50. Ekeradio, Box 131, Temple City, Calif.

KITS, Crystal Radio $1.95, Solar Powered Radio $4.95, Wireless Transmitter $3.95, Audio Telescope $5.95. Lectronix, Box 42 -PE, Madison Heights, Mich. 48071.

PERSONALS

INVESTIGATORS, FREE BROCHURE, LATEST SUBMINIA- TURE ELECTRONIC SURVEILLANCE EQUIPMENT. ACE ELECTRONICS, 11500 -K NW 7th AVE., MIAMI, FLA. 33168.

PERSONAL PROBLEMS got you down? Worried about world conditions? Learn to control your life and affairs through proper use of cosmic law. Free literature. Write today! Lemurian Fellowship, Dept. 628, Romona, Cali- fornia 92065.

BILL PROBLEMS? Poor credit no trouble. Not a loan company. Send for free application. Automatic Acceptance, 318PE Broadway Blvd., Reno, Nevada or 307PE Pocasset Ave., Providence, R.I.

SECRET LAW Wipes Out All Debts. Immediate relief. Free details. Counselor -48, Harlingen, Texas 78551.

HELP WANTED

YOUNG HOBBYIST wanted some evenings to help build projects with experimenter lacking time. Write Thein, 520 Fifth Avenue, New York 10036.

ELECTRONICS TECHNICIAN -Excellent opportunity for experienced person to work in research lab. Should be capable of troubleshooting electrical equipment, testing circuitry using oscilloscope, operating basic power tools. Many company benefits. Convenient to public transpor- tation. American Medical Association, 535 N. Dearborn Street, Chicago, Illinois. 527 -1500, Ext. 326.

RUBBER STAMPS

RUBBER ADDRESS STAMP $1.00. Signature $2.88. Free catalog. Jackson Products, 1433 Winnemac, Chicago, III. 60640.

"FEMALE HYPNOTISM" Exposed, explained! "Secret PHOTOGRAPHY -FILM, Method" -they never know! $2, rushed. Guaranteed! EQUIPMENT, SERVICES Isabella Hall, Silver Springs, Florida.

HYPNOTIZE INSTANTLY! Secret Methods! Nerves! Fe- males! Magnetic Healing! Self- Hypnosis, Illustrated Course, $2.20. Brugenheimer Publishers, Box 158 -E30, Lexington, Mass.

HYPNOTIZE FEMALES!- Unnoticed! Instantly! Nerves! Send $2.25. Research Enterprises, 29 -SN21 Samoset, Woburn, Mass.

December, 1966

MEDICAL Film -Adults Only -"Childbirth " -1 reel 8mm $7.50 -16mm $14.95. International -E, Greenvale, L.I., New York.

SCIENCE Bargains- Request Free Giant Catalog "CJ" -148 pages -Astronomical Telescopes, Microscopes, Lenses, Binoculars, Kits, Parts. War surplus bargains. Edmund Scientific Co., Barrington, New Jersey.

119



MOVIE FILMS

CHRISTMAS GIFT PROBLEMS? -SOLVE THEM EASILY WITH 200' 8mm EASTMAN COLOR FILMS. All the excite- ment ... action . entertainment of: SKI MODERNE, $22.95... '66 ROSE BOWL FOOTBALL (UCLA vs. Michi- gan State), $19.95 ... NBA BASKETBALL, $17.95... '66 INDY 500, $13.95 -each postpaid. Order for yourself, too! SPORTLITE FILMS -PE, 20 North Wacker Drive, Chicago, Ill. 60606.

MAGAZINES

ELECTRONICS FROM JAPAN? English- Language monthly magazine covers all Japanese Electronics. $10. per year subscription. Sample Copy $1. Dee, 10639 River- side, North Hollywood, California 91602.

EDUCATIONAL OPPORTUNITIES

LEARN While Asleep. Remarkable, Scientific, 92% Effec- tive. Details Free. ASR Foundation, Box 7021, Dept. e.g., Lexington, Kentucky. HELP WANTED advertisement in newspapers nationwide prove urgent demand for Draftsmen. "Quick- Learn" home -study plan has helped thousands beginners succeed. Good Salary! Clean Work! "DRAFTING CAREER KIT" sent FREE! Write: North American School of Drafting -MB, Newport, California 92660.

PROFESSIONAL Engineering, Electronics. Free Prospec- tus. CIST, Suite 695, 263 Adelaide Street, West, Toronto, Canada.

EMPLOYMENT INFORMATION

EMPLOYMENT Resumes. Get a better job & earn more! Send only $2.00 for expert, complete Resume Writing Instructions. J. Ross, 80 -34 Kent St., Jamaica 32, N.Y., Dept. PE.

FOREIGN and USA job opportunities available now. Con- struction, all trades. Earnings to $2,000.00 monthly. Paid overtime, travel, bonuses. Write; Universal Employment, Woodbridge, Connecticut 06525.

MISCELLANEOUS

WINEMAKERS: Free illustrated catalog of yeasts, equipment. Semplex. Box 7208, Minneapolis, Minn. 55412.

BEERS, PEACH BRANDY, WINES- Strongest Formulas, $2.25. (complete brew supplies hydrometers catalog 100) -Research Enterprises, 29 -D Samoset, Woburn, Mass.

LEARN Radio Announcing! Magazines, Beginners Books: Deejay, Box 11 -PE, Aberdeen, South Dakota 57401.

LEBANON Holy Land Koweit, REMAILING $1.00 airmail. Box 5569, Beirut.

STOP AUTO THIEVES THE EASY WAY!! Affix Auto Alarm Decal to your car window (whether you have alarm or not) and burglars stay away! Send only $1.00 for two authentic decals to: J. Ross, 80 -34 Kent St., Jamaica, N. Y. 11432, Dept. PE.

STAMMER -Stutter -No More. (Dr. Young.) Write: Gaucho, Box 9309 -E8, Chicago 90.

ELECTRONICS MARKET PLACE Continues to Show Steady Growth! Our more than 400,000 monthly buyers eagerly await the offerings in POPULAR ELECTRONICS' ELECTRONICS MARKET PLACE each issue ... they read, and they buy because they know they can rely on the products and services advertised in the pages of their favorite magazine. You can increase your mail order response substantially by running a low cost ad ($1.00 per word- minimum $10.00) in these columns. Forward advertising copy with your payment today in order to be sure of inclusion in the next issue- February (closing December 1st, on sale January 18th). Send to: Hal Cymes, Classified Advertising Manager, POPULAR ELECTRONICS, One Park Avenue, New York, New York 10016.

POPULAR ELECTRONICS

DECEMBER 1966

ADVERTISERS INDEX

READER SERVICE NO. ADVERTISER PAGE NO.

I Allied Radio 93 American Institute of Engineering &

Technology 100

American Radio Relay League, Inc 108

2 Amphenol 5

3 Argos Products Company 92

4 B &K 40

5 Blonder Tongue Laboratories, Inc 90

6 Burstein -Applebee Co 106

Capitol Radio Engineering Institute, The 7

Cleveland Institute of Electronics ....I6, 17, 18, 19

7 Cleveland Institute of Electronics 33

Conar 30

9 Delta Products, Inc 91

DeVry Technical Institute 3

10 E.C.I. Electronics Communications Inc 84

II EICO Electronic Instrument Co., Inc 23

12 Eastman Kodak Co 25

14 Electro- Voice, Inc FOURTH COVER 13 Empire Scientific Corp 93

46 Erie Technical Products 20

15 Finney Company, The 83 47 Garrard 6

16 Grantham School of Electronics 98

17 Hallicrafters 11

18 Heath Company 95. 96. 97

19 IMC Magnetics Corp 4

20 International Crystal Mfg. Co., Inc 21

21 Jerrold Electronics Corporation 29

22 Johnson Company, E.F 38

23 Knight -Kit Div., Allied Radio 28

24 Kuhn Electronics 94

25 Lafayette Radio Electronics 85, 86

26 Milwaukee School of Engineering 39

27 Mosley Electronics, Inc 14

28 Multi -Elmac Co 32

National Radio Institute ...SECOND COVER, I, 92

National Technical Schools 34, 35, 36, 37

29 Nova Tech, Inc 13

30 Olson Electronics Incorporated 114

31 Pearce -Simpson, Inc 12

Petersen Radio Co., Inc 89

RCA Electronic Components and Devices THIRD COVER

32 RCA Electronic Components and Devices 31

RCA Institutes, Inc 102, 103, 104, 105

48 Ray -Tel 29

33 Regency Electronics, Inc 8 9

34 Sams & Co., Inc., Howard W 99

35 Scott 88

36 Sonar Radio Corporation 101

37 Squires- Sanders Inc 98

Sydmur Electronics Inc 94

Technical Training International, Inc 10

38 Telex /Acoustic Products 111

39 Texas Crystals 108

Tram Electronics, Inc 26

40 Turner Company, The 109

41 United Audio 107

42 United Radio Co 117

43 University Sound 106

Valparaiso Technical Institute 100

44 Weller Electric Corp 27

45 Xcelite, Inc 87 CLASSIFIED ADVERTISING 115, 116, 117. 118,

119. 120

Printe,) in l s,.',. 120 POPULAR ELECTRONICS



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TOUCH -TO -TALK

COMMUNICATIONS

MICROPHONES

Model 619 Dynamic $28Pó

Model 119 Ceramic $16Pä

0 These new beauties are tough. No fragile plastics or light-

weight metal. A 400 -ton high -pressure die casting machine turns two pounds of molten metal into a solid stand that laughs at heavy service. And tough baked enamel plus heavy chrome plating guarantees lasting good looks.

Just touch the big bar to talk. It latches on with a simple, sliding motion. Or move it to the grip -to- talk position on the stand riser in just minutes, with only a screwdriver. The DPDT telephone -type leaf switch will last a million calls or more. It operates both voice and relay circuits, with optional electronic switching available at the end of the 619 (Hi -Z) and 719 cable.

All models are omnidirectional, and come complete with heavy -duty cable. Most economical is the Model 719 ceramic. Response is from 80 to 7,000 cps at -56 db output.

For top quality, choose the Model 619 dynamic models with exclusive E -V Acoustalloy diaphragms. Smooth, peak -free response from 70 to 10,000 cps at -56 db output in- sures highest talk power and full modulation. Choose either Hi -Z or balanced Lo -Z model.

Try one of these rugged new beauties today. You'll find that your rig never sounded - or looked - so good!

ELECTRO- VOICE, INC. Dept. 1262P, 630 Cecil Street

Buchanan, Michigan 49107

gker0- 01CC. SETTING NEW STANDARDS IN SOUND

*We cover our bet with a lifetime guarantee. If any 619 or 719 ever fails, just send it to us. We'll repair it at nominal cost. But if there's even a hint that our workmanship or materials weren't up to par, the repair is on the house - even 30 years from now! Fair enough?

CIRCLE NO. 14 ON READER SERVICE PAGE www.americanradiohistory.com


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